CIS,Megasquirt, Bosch, or other FI conversion->Start here

[Jadewombat]

Please anyone and everyone add some basic guidlines of fuel injection conversion in here geared toward new users, and no one method promoted better than any other(i.e. single butterfly throttle bodies vs. progressive or duals, etc.). Pros and cons of each conversion are welcome as long as any one system is not promoted as better than the others(i.e. all systems have their drawbacks such as cost, complexity, tuneability, availability, etc.). Please check your spelling, too as this will be up for quite a while.

Let's get started.

Some terms you should be familiar with:

-Fuel injection(abbreviated FI)
-ECU, electronic control unit or the brain that controls all of the components
-Throttle body(TB), this is what takes place of the carb. to draw air into the engine, this may or may not have a throttle position sensor(TPS) and or a wide open throttle(WOT) switch depending upon the application
-Auxiliary air valve, this gives a cold engine a little extra air at startup. 12V is applied to the air valve to gradually close it over a few minutes as the engine warms up
-Cold start injector, as a cold engine is cranked this extra injector squirts some extra fuel to get the engine started
-Idle Air Control valve(IAC), an electronically controlled valve which bypasses the throttle plate to control idle speed.
-Port injection, the fuel injectors are placed at or near the intake ports on the intake manifold of the engine
-Throttle body injection, the injectors are placed near the throttle body, typically much further away than a port injection system
-Pulsed injection system, an injection system where the computer electrically controls the firing of each injector(e.g. Bosch D-jet, L-jet, LH-jet, Motronic, aftermarket, etc.)
-Programmable system, just like it sounds(e.g. Megasquirt(MS), Electromotive, SDS, 034 injection--AKA standalone system)
-Constant injection system(CIS), a Bosch developed mechanical injection system that was popular on many european cars from the early 1970s to the early 1990s. A central fuel distributor controls the flow of fuel to the each injector by a swing arm attached to a piston in the middle of the fuel distributor drawn up and down by the air pulled into the engine.
-Fuel pump, these operate at usually much higher pressure than a carb'd car. On a car with a carb. the fuel pump will put out less than 5psi., on an injection system it can produce up to 120psi(CIS) depending on the system. Typically, pulsed systems operate at 35-40psi.
-MAP sensor system, the computer determines how much fuel to inject in the engine based on manifold pressure(Bosch D-jet, Megasquirt, etc.)
-MAF is a hot wire sensor system, a current is passed through a wire and the air sucked into the engine going past the wire cools it, in turn the computer adjusts the amount of fuel to inject in the engine based upon how much air goes past the wire(Bosch LH, Motronic, etc.)
-VR, variable reluctance sensor used for picking up the signal from a trigger wheel for ignition inputs to the ECU

[doc]

Good idea! The forum moderator can assist.

doc

[Jadewombat]

Which system?

If you're still deciding over what system to use, let's cover a few basics about some of the systems including cost, availability, ease of setup, and tuneability. The Bosch systems are mentioned first for swapping to an air-cooled engine and geared toward the user who isn't as concerned about programming for optimum horsepower--i.e. these systems are more 'set it and forget it.' A list of the car models, years, and types of systems are covered in the books 'Bosch Fuel Injection and Management' by Charles O. Probst, and 'How to Tune and Modify Bosch Fuel Injection' is also a great place to start.

CIS-There were millions of cars produced with CIS(mostly European), many of which are still running today. There are a few Bosch FI books on the market which cover all the models which used CIS. It is a very simple system to adapt and maintain. If you do have problems with it, a CIS fuel pressure gauge(about $80) will track down what the problem is. There are essentially three CIS systems.

CIS basic - this is a pressure based only system, no computer controls any of the components(common on cars from the early 70s to early 80s). The only 'electronics' are a relay which kicks the fuel pump on when it gets a signal from the ignition when it fires. As described above, individual fuel lines to each injector are routed to a central fuel distributor which has a piston in the middle of it. When the throttle body opens, an arm attached to the piston raises the piston allows more fuel to spray into each cylinder. The injector is constantly spraying, varying only the rate it sprays at, constant injection system(CIS). A warm up regulator is attached to the engine block which leans the mixture out from startup as the engine warms up. This is the easiest system to set up and maybe a good transition for a hardcore carb. guy to get used to. The only adjustments are a mixture screw on the airbox and idle speed on the throttle body. This is however the most limiting as far as tuneability. Since CIS works based on airflow, it adapts to any engine you put it on, especially the basic system(as long as the cam is not too heavy at idle). The mixture you set at idle works across the rev. range, just like a carb. In order to 'see' what's happening at the top end, you can use the same trick a lot of the drag racers use now which is a lean-rich meter hooked to an oxygen sensor. This still doesn't affect the operation of the CIS system, it just lets you know what is happening up top. http://www.sdsefi.com/mmm.htm or http://www.haltech.com/wideband_lambda.htm A CIS basic setup from a junkyard car can cost next to nothing(a list of all the stuff you'll need will come later), keeping in mind completely gummed up components may or may not free up with a little carb cleaner(i.e. it's better to pull stuff from a running car, or recently run). All replacement components(fuel distributor, injectors, seals, etc.) are still somewhat readily available on the market new and used, the most expensive component to replace is the fuel distributor $200-? and the injectors $40-80 each. To adapt to an air cooled engine, everything could be done in one long weekend but would be better done over a couple of weekends. The most challenging adaptations are mating the CIS fuel lines to the pump and return lines and tying this into the fuel tank, wiring a relay for the fuel pump, mating the CIS injectors into the intake manifolds, mounting the airbox, and fitting the cold start valve into the intake manifold.


CIS with lambda - This setup does have a computer which utilizes an oxygen sensor(lambda) to make tuning adjustments throughout the rev. range of the engine(early 80s to late 80s). This system is very similar to CIS basic though a little more integrated. These systems are also very adaptable to most any engine as the system is still based on air flow. The same two adjustments of mixture and idle are all that is needed. The systems are better than CIS basic as more hp and better fuel mileage can be achieved as the computer compensates and adjusts the return line pressure based upon input from the oxy sensor as the engine speeds up. Early versions of CIS used an iron(black) distributor with a modified fuel injector to control return pressure, later versions used an aluminum(silver) distributor with an integrated control valve known as CIS-E. CIS w/L is even more readily available than CIS basic new and used, well for obvious reasons as there were more of them on the road. Cost for replacement parts is similar to CIS basic with the addition of sensor costs. The ease of adapting to an air-cooled engine is similar to CIS basic with the addition of welding in a bung for the oxy sensor in the exhaust manifold, mounting the computer and harness internally, and mounting the various air and or water sensors for the computer.

CIS Motronic - This is mentioned only to cover our bases but not really recommended for adapting to your engine(late 80s to early 90s). These systems look similar to CIS w/L(CIS-E) externally, although the computer is much more integrated. They are not very adaptable to other types of engines as the internal maps built into the computer are specific to that type of engine the injection came off of(i.e. they do not like changes). Motronic is only mentioned if you happened to be swapping the whole engine from a donor car into yours, then they would work(i.e. putting a 16V 2.0L swap into a bug, etc.).

The Bosch pulsed injection systems:

D-jet - This a very good, very reliable electronic system that came on late 60s to early 70s Type 3s, 4s, 914s, Mercedes, and some Cadillacs. Many of these systems still run today after over 40 years. They are easy to diagnose and many parts are still available. The drawback is they do not like heavy modifications. These systems are programmed to run off of manifold pressure(MAP), temperature, and throttle position. A couple of mild mods to your engine should be fine, but if your stock engine is modified too much D-jet will not be able to keep up. The obvious answer is if you have stock 1600 and bore it out to say a 1955cc, is to put injection from a bigger engine(like a Type 4). This will work, again as long as the cam is not too heavy at idle. It IS possible to modify, reprogram if you will, the D-jet 'brain' for a modded engine, but this is not something for someone not overly familiar with these systems or especially the new user. If you start tinkering with it and get stuck, oh well. These systems are cheap, a stock setup could be had for almost nothing off a parts car, the most expensive replacement is the three-outlet fuel pump which can cost up $100-300 rebuilt. Setting up a D-jet system, on a Type 1 for instance, would take a long weekend. As long as all parts are accounted for, the trickiest part would be installing larger fuel lines from the front to the back of the car.

L-jet - These are also very good, very reliable systems that started appearing on 914s, Type 4s, Buses and T1s in the mid-70s, then BMWs, etc. There is an air 'flap' in the airbox which opens according to the air flow into the engine when the throttle body opens. A resistor on an arm hooked to the air flap and input from the oxy sensor tells the computer how much fuel to inject into the engine. Since this system is based on air flow, it is very adaptable to engine mods, to a point. If you go too extreme you are limited by the system's throttle body, intake manifold, and air flap size along with the pulse duration and pulse frequency of the injectors. You can optimize the induction with bigger components and trick the computer to run a little richer overall, but you will still be limited with a very heavily modified engine. Again, if you have a smaller engine you bore out and adapt an injection system from a bigger engine, this will work. This, again, is not to say L-jet is not a good setup on a performance engine, I saw a L-jet on a draw through setup with a turbo, the owner only had to release some of the spring tension on the air flap to get it to work on his engine. Swapping airboxes with different computers is not recommended. Most all L-jet parts are still on the market with the exception of some of the airboxes which are getting harder to find, the airbox being the most expensive part to replace in the system. Fitting L-jet would also take a long weekend as long as all components are accounted for. The hardest part of the install is installing the fuel lines through the car, wiring the relays for the computer and fuel pump, mounting the airbox, and welding in a bung on the exhaust for the oxy sensor.

LH-jet - This setup is similar to L-jet but instead of an air flap a wire(mass air flow-MAF sensor) has current passed through it to heat it(on BMWs and Volvos in the mid to late 80s). As more or less air passes by the hot wire cooling it, the computer must compensate to keep the wire hot and is able to gauge with the oxy sensor how much fuel to inject in the engine. These systems have very little air restriction when compared to an L-jet system. As LH is also based on air flow(actually air density) these systems are adaptable to different types of engines. As Volvo engines tended to be sizeable(over 2L) compared to an air-cooled engine, an LH system would have no problem keeping up with a highly modified T1 or T4. Setup is similar to an L-jet setup, although cost of the system may be a little more than free from a junkyard as parts off of BMWs and Volvos tend to be pricey. The biggest cost in replacement parts is the fuel pump and MAF meter.

Digifant - This was an injection system developed by VW using Bosch components using an air flap meter similar to L-jet systems with the exception of the Corrado which used a MAP sensor(mid 80s to early 90s) with ignition and knock sensing built into the computer. The early systems which came on Vanagons controlled only fuel injection called Digifant I, this Digifant I setup also came on Corrados but used a MAP sensor and controlled the ignition system. Digifant II systems came on Golfs and Jettas and utilized an air flap with ignition control. The systems proved to be very reliable and somewhat adaptable to modifications.

Motronic - This is the most advanced pulsed system which controls fuel injection and ignition with the use of a hot wire sensor(early 90s-today). This system controls the firing of each individual injector vs. firing in pairs or batch firing. Motronic is similar to CIS motronic in that a few modifications are OK but too many and the system will register it as an error code based on the internal MAPs. The Motoronic can be reprogrammed, but is not something for the weekend mechanic.

Programmable systems:

These are DIY fuel injection systems that have become simple enough and affordable enough for the weekend mechanic over the last 10-15 years. These systems may or may not be more affordable than a system off a production car(junkyard) but the advantage is they are new(the central brain at least in most cases) and you can control precisely how much and where in the powerband your engine makes power.

Megasquirt - This is arguably the cheapest, most extensively used aftermarket FI systems around. You purchase the central controller or brain, but have to supply the other components for the system to work(injectors, harness, pump, sensors, manifolds, etc.). The system works on inputs from a MAP or MAF sensor along with temperature, throttle position(TPS), ignition, and you have the option of using an oxygen sensor. The newer version 3.0+ (MS Extra) you can also utilize a hotwire sensor or MAP sensor or both, along with knock sensing ignition control a variety of ignition configurations (distributor, EDIS, MSD, COP, or CNP). You can control up to 16 injectors with odd cylinder combinations(such as 3 or 5 cylinders), as well as boosted engines(up to 21psi). All programming is done from a computer, the software used to program is freeware downloadable from the MS website or Tunerstudio (recommended). You can control how long the pulse duration is, how many times the injector fires per second, where in the power band(rev range), along with start up(richer) sequences as well as the ignition with more advanced kits. The setup and support are extensive http://www.megasquirt.info Costwise, the controller is only a little over $100 unassembled (if you don't mind soldering) and a little over $200 for a basic system assembled. All other components could be bought new(injectors, pump, wiring harness, etc.) but if you're on a budget you have the option of using the components from a junkyard car. Powerwise, the limiting factor will be manifold and throttle body size as performance of the engine is increased. BE ADVISED, even if you buy a fully-assembly kit or DIY kit, due to the nature of megasquirt usage you WILL be heavily involved in a lot of research and reading to find answers and instructions because this is one of the lower priced systems on the market.

Simple Digital Systems(SDS) - This is a very straightforward pre-assembled system for different cars (including VWs) which doesn't require a computer to program, but offers the same extensive tuning of an aftermarket system. These systems utilize a MAP sensor and TPS along with a temp. sensor(oxy sensor optional), are able to control ignition up to 9750 rpm with the option of crank-trigger, work on boosted engines, and you have the option of knock sensing, fan control, supercharger clutch, etc. Their complete systems are supplied with the brain, LCD dash module for programming, injector and sensor a pre-assembled harnesse for your car and plug in cables, dash module for extra lean rich control, and they sell any other the necessary components if need be(sensors, relays, even injector bungs). Their connections are designed to work with Bosch injectors. Their website is very extensive and straightforward, http://www.sdsefi.com A typical system can cost just under $1000 to $1700, but this system is more complete compared to an Megasquirt system(i.e. you get what you pay for and this will save you vast amounts of time and potentially headaches). Their website is a good read, funny at times too. A lot of the info. and setup they give is geared toward using the factory Bosch FI stuff(e.g. if you had an L-jet equipped bus or something, this system would be pretty much plug and play after mounting the TPS on the TB).

Electromotive - This was one of the first aftermarket systems to come out on the market which controls fuel injection and ignition. Using GM style sensors, the system uses a MAP sensor and TPS along with temp. controls to control 1-8 cylinders(except 5) and 12 cylinders with the option of dual plug ignition control. The ignition pickup is by crank trigger, a rev. limiter is built into the controls and the system is able to work on boosted engines. All programming is done from a computer and there are some extra functions such as extra injector control, fan and alternator control(for drag racing), shift light, torque converter, etc. These systems are complete but tend to be pretty pricey. http://www.directignition.com

Weber Redline - This is another MAP sensor based system utilizing engine temp., TPS, air temp., and oxy. sensor inputs and crank-trigger wasted spark or COP applications are possible. The system is fully programmable for different performance applications from a computer. These systems are all-inclusive and plug-and-play, as in a kit is designed specifically for T1 engines, more or less like the version of carbs Weber would sell for years in different setups(DCOE, IDA, etc.) but with injectors in them instead of floats and jets. These kits are very pricey at over $3000 for a complete system, but again they come with everything to fuel inject your T1 engine including the manifolds. The limiting factor seems to be limited to dual throat throttle bodies(no single), and limited only to the T1 engine(although with the correct base intake manifolds and linkages it should be possible to inject a T4 as well). http://www.redlineweber.com

Haltech - This was one of the first programmable aftermarket systems on the market, an Australian made FI system with a range of different ECUs controlling 1-6, 8, 10 or 12 cylinders and ignition control up to 16K RPM using MAP, temp., oxygen, and TPS sensor inputs on N/A or boosted engines. The ECU is capable of sequential injector firing, direct or wasted spark ignition firing, boost control, data logging of the engine, and an optional digital dash display/control which is really neat. The ignition pickup is either through a pointless distributor or crank trigger sensor. These systems are complete with harness, throttle bodies, injectors, etc. available through Gene Berg http://www.geneberg.com

034 Motorsports - A fully programmable aftermarket system which utilizes a MAF sensor, can run up to 1-8 cylinders sequential (depending upon kit) or 1-12 cylinders batch fired, distributor or crank-trigger ignition with wasted spark by coilpack or coil-on plug at a good overall cost. They offers universal kits and all sensors for adaptations. Very cutting-edge and they have a very good reputation. http://www.034motorsport.com/034efi-eng ... -c-22.html

CB Performance - Another longtime provider of fuel injection systems and components that has been in the VW aftermarket. Supplies complete kits with dash tuning modules or individual components for converting a VW engine to FI (manifolds, fuel rails, etc.). Kit works on MAP based sensor and utilizes GM/Ford sensors and works with most ignition systems including a CB crank trigger system. http://www.cbperformance.com

Big Stuff3 - Supplies universal (for VWs in this case) kits, sensors, and components. Sequential fuel controller up to 16 cylinders individual, utilizes oxygen sensor, and capable of COP ignition. http://www.bigstuff3.com

**Of note on aftermarket programmable systems, many of them require you to plug in with a laptop or other type of computer. The technology to communicate between ECUs and laptop can be very troublesome. You can spend several hundred or even thousand dollars on a system then come to find out you cannot even communicate with the ECU because your computer does not have the right connection. Most modern computers use a USB port now for all communications. Most aftermarket ECUs do NOT use a USB because of the cost associated with maintaining and supporting the USB drivers. Many aftermarket systems use either a 9 pin serial port or RJ11 connection (phone jack type--uses four wires instead of two for a dial-up connection). You will have to crossover using a RS232 9pin to USB converter (and then a serial to RJ11 adapter if an RJ11 connection is required) to get the correct connection established. Finding the correct communications port and baud speed/settings all can be very frustrating and time consuming. Just be aware of this ahead of time. Look at your computer, does it have a 9 pin serial port (two rows of 5 and 4 pin holes)? If you don't have this, the video card (15 pin) or phone jack (has only two wires) will not work. The computer will only communicate externally through the USB port. USB issues collection of threads.**

[Piledriver]

I have run a CIS-E system without the computer for about ~18 months now. (~30++ K miles)

The control current to the meter is set with a potentiometer off a 5V regulator, a couple of resistors for fail-safe current limiting complete the system. Sorta CIS-basic with an electric control pressure adjustment.

It will also flow 350cc/injector with the control current at 125mA... totally unmodified. (later units were -10-+10 mA, I think those were actually the true "Motronic" units)

Runs great, gets ~35 MPG in my Pile 914.

The -E meters are MUCH newer and typically in better shape vs the basics, and can support 180+ HP.

[Jadewombat]

I'm ready to get started, what do I need?

You've narrowed your choice down to the system you want to run so we'll cover what you need to either pull from your donor car or collect(buy) for your new system.

Retrofit - This is where you plan on using a O.E.(orignal equipment) system ranging from using all used components, preferably off a car you could hear run or that has been sitting less than a year(the gas will varnish if it sits too long and clog everything up), to using some components used and others new(e.g. computers rarely go bad but fresh injectors can improve the performance of the setup). If you buy a setup off of e-bay or at a swap meet or wherever, just be aware not everything may be there that you need.

CIS-The checklist for a CIS basic system of stuff you need is the airbox/airflow meter/fuel distributor/boot assembly, injectors/injector lines, cold start injector and ambient air temp. sensor/electrical connector, warm-up regulator(WUR) and electrical connector, throttle body, fuel pump and accumulator(canister looking thingy), auxiliary air valve/electrical connector, the fuel pump relay, the banjo lines to and from the fuel distributor, and at least cut some of the hard fuel end off that threads into the banjo lines or take the whole hard line with you. This last part, there are options about mating AN fittings onto these ends(push on line and hose clamps are not an option though, this is high pressure stuff-->80psi). There is a specialized tool for pulling the injectors to simplify things, a long screwdriver and penetrating oil helps too.

Getting a CIS w/lambda or CIS-E) system, you will need all of the above plus the computer, oxygen sensor, the harness to the computer and harness to all the sensors, return line valve(should be next to the fuel distributor, and the various temp. sensors(usually water temp. sensors in coolant outlets), and the fuel pump box if equipped(later Golf or Jetta). If you plan on running this with a turbo, you might look into getting a setup off a mid-80s turbo Volvo or Saab which had a boost sensitive regulator with it.

A photo of a CIS w/Lambda setup in a rabbit


D-Jet - The checklist of a D-jet setup, you'll want to get the three-outlet fuel pump(up near the front end), the fuel pressure regulator, the ignition distributor, the MAP sensor(usually mounted up on the wall off to the side), the brain, the harness/relays, all the injectors/fuel rails, the cold start valve(extra injector), the auxiliary air valve, the intake manifolds, the throttle body, the hard fuel lines running under the car, vacuum lines(note their locations), and all the various sensors(especially the tiny one in the air cleaner). The FI harness should disconnect from the main wiring harness but you might think about grabbing the circuit board to simplify things as well if the car has one(914s).

L-Jet - The checklist for L-jet of stuff should include the airbox/airflow meter, the wiring harness which should disconnect from the main vehicle harness(on most air-cooled VWs this is the case), the fuel pump/pressure regulator, fuel lines/fuel rails to the injectors, intake manifolds/throttle body, various sensors(most notably the tiny one on the cylinder head and thermo time switch), all vacuum lines, injectors/brackets holding the injectors in place, cold start injector, auxiliary air valve, the EGR you probably won't need(it's a good idea to just plug off this hole) but grab the pipe if it's easier to just hook it back up if it hasn't rusted through yet, the brain, oxygen sensor(if equipped), and there should be two relays you want to grab off the firewall(T4 buses) and clip off a couple inches of extra wiring. The air and fuel filters you'll want to change and should only be grabbed from the donor car as a reference or if they were very recently changed.

L-Jet tuning pages http://www.ratwell.com/

Aftermarket fitment - This is where you buy the aftermarket controller new(MS, SDS, etc.) and have the option of using some or all of the O.E. components to using some or all completely new parts. There are lists of all the parts you will need from the manufacturer of the controller, but a short list is a 40-50psi fuel pump, MAP sensor, TPS, injectors, harness, fuel rails, temp. sensors, aux. air valve, oxy sensor(optional), TB and intake manifolds, and fuel pressure regulator.

If you plan on using Ford EDIS for your ignition(specifically with MS) you'll want to grab the ignition system off a mid-90s Escort or Mercury Tracer, a list of parts found here http://megasquirt.sourceforge.net/extra/us-edis4.html They recommend here taking the head off the car, jamming rocks in the cylinders and reattaching the head to keep the crank from turning, this is a bit excessive. And old mechanics trick to keep the crank from turning is to clamp an old accesory belt very tight around the crank pulley(or serpentine, whatever the case is) and set a pipe in the excess loop of the belt. Wedge the pipe up against some strong part of the car and this will keep the crank from turning.

You can use a new aftermarket controller with a stock harness and components from a Bosch pulse-injected car(D-jet, L-jet, etc.) which may or may not simplify things, but will at least keep the cost down vs. getting all these things new. Keeping in mind though, most aftermarket controllers are MAP based systems so you may need to buy a new MAP sensor and TPS and sensors if the system you're retrofitting from wasn't a MAP system to begin with. If you need different, or bigger, or new injectors, along with other components(complete systems, etc.) a good place to source aftermarket FI stuff is usually in the forced induction sections of usegroups such as this, VWVortex http://forums.vwvortex.com/zeroforum?id=844 , VWFixx http://www.vwfixx.com/forums/index.php?showforum=246 (VW Exchange now) http://www.vwexchange.com/index.php?a=5&b=229 , Ebay of course, etc. Also of note, for high performance setups a lot of peole are going with CIS pumps with a regulator as they supply a lot of volume and are relatively cheap compared to high output aftermarket pumps.

[Piledriver]

Accumulator too.

Will run without it, but better with it.

[Jadewombat]

OK, I think I have everything I need to inject my engine, how do I...?

Installation:

Intake manifolds, throttle bodies, end castings - It's a good idea to keep these things in mind before you start installing/fabricating. The intake manifold and TB size can be a limiting factor as far as horsepower if they're too small, but this is not absolute. Bigger intake manifolds are in most cases a good idea(i.e. CB Performance FI end castings vs. small T1 stock end castings), but while a bigger TB(s) 'may' improve the horsepower numbers of your engine you may also lose a lot of driveability. For example, rabbits came with progressive throttle bodies originally. Weber was selling an oversized single throttle body as a replacement in the mid-80s for a short time. This made the engine very 'stabby' when you touched the gas pedal. Keeping this in mind, if you inject your engine and run a single TB, it may be difficult to tell the difference between a sharp horsepower increase from before with the carb. and a sharp change in throttle response. Manufacturers spend years and millions of hours and dollars in research to best match the throttle body with their intake manifold/runners and engine to make it smooth for the public while making decent HP and TQ(manifold design is a very dark art). This isn't to say single throttle bodies are bad, but it is highly recommended you do some homework and find out what other people have run sucessfully on their setups instead of just grabbing a junkyard single TB to make it work with your injection system.
As far as intake manifolds go, without getting too hard and heavy into airflow characteristics, shorter intake manifolds(such as duals) tend to produce more HP higher up in the powerband while longer, more curved manifolds tend to produce more TQ lower in the powerband.



In the pictures above, the Porsche flat 16 is from a racecar. Racing engines in most cases, are extremely high revving-high HP output motors with low TQ output as they don't need it(F1 and rally cars have similar setup). The lower engine is a twin-turbo VW 16V built for the street with very long intake runners(Toyota 1.8 engines carried similar design). Some manufacturers(such as BMW and Mitsubishi) have used variable intake manifolds to adjust to the driver's demands depending upon whether maximum hp or torque or a combination is required. Also keep in mind, the air cleaner acts as part of the intake as well. Using a single throttle body vs. duals also opens up another whole can of worms, i.e. will it flow enough? In most cases you need to really ask will the engine(the part past the intake manifolds) be able to draw enough to see the effects of bigger or more flow area.
There's a very good writeup here about the subject with a bigger throttle body being the only thing changed out on the motor, almost no change in hp was seen.
http://www.cartechbooks.com/vstore/show ... apter=4771

Controller, harness, etc. mounting - Computers do not like heat or water or oil or vibrations or anything that isn't a cool(er), dry place than the engine compartment. It's best is to route the harness to where the brain can be stored outside of the engine compartment with an appropriate hole cut in the firewall or access hole big enough for the end of the harness connector and a rubber grommet to seal it. If the harness will not reach, you should locate or fabricate a metal box just slightly bigger than the brain itself, and the appropriate hole/grommet. If you have a very heavy cam at idle and the car vibrates quite a bit, you may consider some rubber washers under the mounting bolts for the brain/box. The same grommets should be installed around your fuel lines if they're routed through the front tin on the engine to keep them from shearing. The harness and fuel lines shouldn't sit on a surface that gets excessively hot either to prevent melting/drying out of the wires or lines.

Fuel pump/lines - Most all cases you will want the fuel pump as close to the tank as possible. FI pumps are better at pushing fuel than they are at picking it up(sucking) out of the tank. You could use a carb. electric pump(5psi.) as a feeder pump, but this isn't recommended as it may not supply enough volume(especially with CIS) and the pre-pump can be one more thing to break. If your car was carbed originally(like a bug) you'll notice the fuel line running from the front to back of the car is very small. Fuel injected cars normally come with two lines to and from the tank and are usually bigger in diameter. A large, very long American car brake line works very well with the ends cut off for use as a fuel hard line. On this same bug, you could install a bigger supply line and most likely use the stock hard line as a return line to the tank(at the fill spout) since the pressure is much lower on its way back to the tank, or 'tee' the lines back into each other on the suction side of the pump. A good diagram of this can be found here http://www.cbperformance.com/pdf/QTEFII ... Manual.pdf Of note, CIS pumps are very thirsty. All of this really depends on the system you're going to use and the type of car it's going into. In the case of a newer style fuel rail(that doesn't use slip on lines) or CIS system with AN type fittings or banjo fittings, you may have to buy the correct endpieces and have these fitted at a hydraulic hose shop near you. Of note, CIS fittings are metric and these systems run at very high pressures(~80 psi) and hose clamps will not secure it, everything has to have a screw on it or banjo end fitting that can be torqued down (the return side is ~40psi). The fuel lines running through the tin or firewall you will want to run grommets or very thick sleeved material as the engine vibrations can wear a hole through rubber or steel lines. If you're installing a regulator, you'll want to mount it where you can get at it if need be (if you're retrofitting a D-jet system, these are very sensitive to fuel system pressures).

Fuel injector size and selection - This can be a limiting factor as far as the engine making more horsepower, but it is not necessarily the rule. It depends on what your plans are for the engine. If you have a stock engine, well, simply put most any O.E. system will have no trouble keeping up with your engine. If you have some mild performance upgrades such as a slightly heavier cam and some high lift ratio rockers, a stock system should still work needing a little more fuel across the board(richer mixture) and possibly advancing the spark a little. If the upgrades mean a larger bore engine and high flow heads for example, as stated above, you should consider an injection system off of a bigger motor if you are doing a retrofit, as these systems may come with bigger injectors. If you are going with a CIS system, these are notorious for being able to handle major power upgrades with little modifications needed(especially to the injectors), for reference though, some later Mercedes injectors tend to flow more than the VW, Volvo, etc. injectors. Pulsed injectors are rated in lb/hr. or cc/min. The main reason that O.E. injectors on production cars tend to be 'small' are for emissions control, fuel economy, and smoothness of the engine. If you are using an aftermarket system and emissions or mileage isn't so important but maximum output is, you will need to consider some aftermarket units such as those sold by the speed shops(Jeg's, CB, etc.) because a stock injector simply won't flow enough for the engines demands. By the same token, you should calculate what size injector your engine will need as you don't want the injectors too big because you will be wasting your money and time fitting something the engine can't handle. Except for D-jet or CIS, you can also run a slightly higher system pressure to make an injector flow the like a bigger injector, but it isn't recommended to run too much higher as it will wear on the fuel pump. Most pulsed injectors are interchangeable, the only differences being the older D-jet style plug(less common) and L-jet style(more common) plug and whether they use a barbed fitting with a hose pressed and clamped over the end or a press-in style with an o-ring that squeezes into the fuel rail. The other difference is low or high resistance(impedance) across the injector which should be checked before use in an O.E. system, but most aftermarket systems can accomodate either.
http://www.sdsefi.com/injectors.htm
http://www.ratwell.com/technical/Injectors.html
http://www.robietherobot.com/storm/fuel ... rguide.htm
Calculator - http://www.rceng.com/technical.aspx

Ignition system – There are many options nowadays for different ignition setups, noting that a fuel injected engine will work with the stock ignition(including points). With the exception of D-jet systems, where you need the stock distributor for the computer to fire the injectors, it is possible to upgrade to a different ignition system such as pointless, electronic, coil-pack(wasted spark or direct fire) for better control and more ignition. The old points type systems have their drawbacks as far as swelling of the points with heat decreases the spark, points don’t like to work when they get wet, etc. Pointless systems such as the Petronix Ignitor which replace the points won’t increase hp much but will do a better job of the engine producing consistent, smoother power across the board and under different conditions. An electronic system which still uses a distributor such as MSD or Jacobs will actually produce more hp as a more powerful spark is produced.

The advantage of a crank trigger setup vs. one that uses the distributor is accuracy and response. There is a small amount of play between the distributor gear and the crankshaft gear, much less so with a crank position sensor. The added bonus using a crank angle sensor(VR or Hall sensor) and gear take up less space than the conventional distributor. A VR sensor is a variable reluctance sensor, without getting too technical, works by a tiny magnetic swinging back and forth inside producing an AC voltage as the trigger wheel goes by it. A Hall sensor works by a current being passed through it and a small magnet in the trigger wheel causing the sensor to produce no voltage when the magnet goes by it. A wasted spark setup is where two cylinders share the same coil on a coil pack and there are two firings per cycle for each cylinder. The first firing happens when the fuel is in the cylinder is nearing the end of the compression stroke and at the same time the other paired cylinder is firing after it has exhausted. This exhausted firing doesn’t do anything or is ‘wasted’. Saab was one of the first companies to use multiple coils, most modern cars it is now commonplace. A very popular setup to use now is the Ford EDIS ignition setups with MS. Ford started using distributorless systems in the late 80s, the EDIS setups on the 90s Fords are the most sought after now for use with aftermarket injection systems.

There are a few crank trigger kits on the market now for the Type 1 engine, www.directignition.com www.jaycee-ent.com less so for the Type 4 or where you might need to fabricate a custom mount. When mounting the crank angle sensor in a custom setup, you should prepare for the worst. Example of a Type 4 setup. Ask yourself, if the fan belt were to break and whip around, would it bend the sensor bracket? If it fails, it probably won’t be in your driveway, it’ll be on the upside of a mountain pass in the middle of winter with a convoy of 18 wheelers behind you.

Knock sensing ignition is something to consider if you’re running a motor on 9.0 to 1 or greater compression. Knock begins at about 9-9.3-1 and higher depending on if you’re running carbs or injection, load on the engine, gas quality, etc. Knock doesn’t happen under all conditions but can destroy your engine if detonation goes on too long. Other than running E85(necessitates neoprene or non-rubber components), high octane gas, etc. a knock sensing ignition will detect knock(detonation) at a certain frequency and retard the ignition back a few degrees until it stops knocking(some knocking is not even audible to the human ear). This is not to discourage you from running high(or higher) compression, this is a great way to squeeze more power for relatively low cost involved. Some knock sensing ignitions available with aftermarket programmable systems are Electromotive, SDS, Jaycar ignition(~$100), MS V 3.0, and the Safeguard from http://www.aircooled.net

Airbox/airfilter(s), airflow meter, mounting - As the engine bay on most air-cooleds can be somewhat tight as far as space to mount everything, you should keep in mind a few things about mounting location, size of the airbox/air filter(s), and type of airbox/filter. Of note, just as no major manufacturer mounts the brain in the engine bay, they also don't use open type filters or air assemblies(meaning exposed, AKA 'cold' air injection). While the original carb. oil bath air-cleaners may seem restrictive and not the most environmentally sound nowadays, they were and are far more effective at protecting the engine than a green piece of sponge and chicken coop wire. In general, the idea of an enclosed airbox or filter is to channel air into the engine from outside of the car/engine bay area, the pickup tube being usually near an opening drawing from the outside, while an open assembly will just draw from all around it. While open cone-type filters have become very popular in the last fifteen years on cars, they may produce extra hp and tq but in some cases just the opposite is true http://www.techtonicstuning.com/images/dyno/Dyno07.JPG The theory is simple, if you expose the intake to more area to draw from the engine 'should' produce more power. Cone or open filters get dirty relatively quickly as they suck all available air from around them, whether it's air being rammed in the engine compartment at speed, or hot exhaust air cycling back in the engine compartment due to a bad seal, or air being drawn in to feed the air-shroud. Cone-filters really became popular in the late 1990s on modern cars replacing the stock airbox, but it wasn't long after this that those same aftermarket cone kits suddenly came with a piece of sheet metal and a seal up against the hood to isolate the filter assembly in one corner of the engine compartment, doing essentially the same thing as the stock airbox it was meant to replace. If this is your weekend or second car or racer, this section probably isn't as crucial to setting up your engine.
Exposed filter on Mercedes 16V engine

Early 911 with mechanical injection and enclosed filter

Another consideration is the actual size of the airflow meter and airbox assembly. The bigger or higher output your engine, the bigger the airflow meter and or airbox(CIS, Bosch retrofit, aftermarket) should be to give the engine a bigger volume of clean air to draw from, i.e. try and fit the biggest aircleaner assembly you can--space permitting. Early CIS cars(such as rabbits and Volvos) came with small airflow meters and small airboxes. The picture below is of a metal Volvo CIS airflow meter and airbox which has been very widely used as a 'cold' air intake by running an extended flexible pipe and cone filter. A Volvo box like this offers advantages being run in a tight space such as a bug engine compartment, but offers less advantage vs. a larger airbox assembly as far as reserve air available.

Audi 5000 airbox pictured below.

Of note, early CIS, CIS w/Lambda, and CIS-E airflow meters are interchangeable on different airboxes. If you are using an L-jet system, as stated above, mixing and matching bigger airflow meters with different brains is not recommended unless you have thoroughly researched it beforehand. While many people have had sucess installing a bigger L-jet meter, it may involve some tweaking to get it just right on your engine(essentially fooling the computer). Be advised though that L-jet doesn't like very heavy cams. Heavy cams produce less vacuum draw on the airflow meter as well as uneven pulses. You may have to do quite a bit of 'flap' tuning of the air flow meter by taking the cover off and adjusting the spring tension and or air flap position outlined here.
Another thing to consider, manufacturers(Ford, VW, etc.) have also used remote reserve air canisters to satisfy the engine's needs.
The black bubble canister on the hood of this cabrio is a reserve chamber for the intake

Offroaders and motorcycle racers have also used this trick for years with a tube coming off the intake manifold(the outlet to the brake booster) that goes to a small bottle(boost bottle) to give a small supercharging effect. This makes the intake area, from the engine's perspective, much bigger to draw from. This may also be an option to use if you have a very small space to work with, or simply want to try to squeeze a few more horses out of your setup.


Oxygen sensor/exhaust - If you have access to the donor car, it might be a good idea to grab the nut that the oxy sensor threads into on the manifold(usually it's just a couple of spot welds). If not, you can source one from SDS listed above or you may get lucky at the hardware store. You'll want to mount the sensor where it will collect from all the cylinders, but not too far away, i.e. at the first point where the pipes merge into one point, drill a hole slightly bigger than the oxy sensor tip and weld the nut to the manifold or muffler or exhaust tip. Be careful not to touch the tip of the oxy sensor itself, this is coated with a lead paste and sensitive to keeping it clean, aside from exhaust. Also make sure the wire to the sensor doesn't sit on the hot manifold and melt through.

[raygreenwood]

Nice sticky. Just finally had time to "thumb" through it. One thing ommited from the D-jet list.....is to either get the stock cam or spec out a cam with proper intake valve timing.

As to the original listing....D-jet can be modified to almost any degree....size wise....as long as injector flow volume, intake tract volume, Tb flow rate and cam timing all rise in corresponding ratio....to keep the signature of the TPS correct. It is the signature of the TPS that is narrow in spectrum. Ray

[Redline Weber]

Redline systems are sold, mostly, threw local dealers. The "list price" needs to be quoted correctly to allow the
local dealers to give a discount to a valued customer, just ask one for a discount.

Direct sales are also made for those who are not close to a "dealer".

There are TWO firmware levels. The "B" is for one with a distriButor already fitted. This is a lower cost firmware though
the EMS is the same AND can be "flashed" to the "C" level when needed.

The "C" firmware is for Crankfire, distributorless, engines. The cost is slightly higher, for those without a fitted distribotor ignition it may be
less if viewed as the complete package cost.

Those here that enjoy designing there own intake, injector, pump, regulator, filter system can purchase the EMS alone.

Many have purchased the four cylinder "C" Crankfire ECU, harness, sensors, crank pulley, crank sensor breaket, and DIS coil for $1250.00.

My sugestion, do the math.

BTW, yes, we do ignition CORRECTLY

[koolkarmakombi]

Great sticky.

Could you cover eidis in this too?

[koolkarmakombi]

Great sticky.

Could you cover eidis in this too?

[Jadewombat]

Inspiration by example:

Here are some photos different of setups. Also visit the megasquirt photo page.

CIS in a Type 181 thing, use of '75 and later bug intake manifold center section/end castings/throttle body, cold start injector is CIS, intake pipes are hardware store plumbing stock. Also note the location of the aux. air valve on the intake pipe and thermo time switch mounted in mechanical fuel pump block off plate. Custom made injector lines were utilized here as donor car lines are usually not long enough.



CIS setup that was used in a '66 Bus. Shown here is a Weber progressive carb. center section, '85 and later VW throttle body(all W/C VW throttle bodies are progressive with 2 butterfly valves and have the same bolt pattern as Weber progressive carb.), '75 and later bug end castings. Cold start injector is mounted in the side of the intake and aux. air valve mounted in fuel pump blockoff plate. Hardware store 3" plumbing elbow was utilized along with 3" PVC pipe. Custom made lines from early Volvo injectors with barbed ends were used with nylon line(to get the new line on you set it in hot water or antifreeze and push it over the end). Mounting of airbox/fuel meter was similar to above shown thing, but in opposite drivers' side corner.



A Mercedes 8 cylinder setup shows adaptability of CIS system mounted on a 2.4L type 1 engine. Custom made injector lines were used as well as intake manifolds. Note the fuel meter draws downward to let air into the manifolds, VW and Volvo 4 cylinder type meter draw plate upwards.



1970s Audi Fox with turbo setup and Mercedes 8 cylinder fuel meter. Note 4 of the injectors are used as 'primaries' and the other four as 'secondaries' although all spray at the same time and same amount.



A custom-made airbox for the CIS fuel meter on a Type 1 engine.



A close of aluminum end castings modified so CIS injectors can press into bungs.



A jig setup to drill out aluminum end castings and weld on injector bosses(CIS or pulsed injectors). The jig holds the same angle that this later bug end does, shown here this is to setup for drilling then the end casting pictured is unbolted and changed with the aluminum one. Pulsed injector bosses are available from http://www.sdsefi.com and http://www.034motorsport.com A how-to thread modifying stock end castings.



An aftermarket MAP sensor based system mounted on Type 4 motor. Note TPS on throttle bodies, intake air temp. sensor on airbox, custom made fuel line with AN fittings, and crank angle sensor mounted to crank pulley.



A shot of a corrado throttle body which comes with TPS for use with a MAP sensor system. These can be used with the above mentioned Weber progressive center section. In this photo it may look like a single butterfly, but these are actually progressive with 2 butterflies.



The stock throttle body and intake manifolds used on 'new' old-style beetles in Mexico are also an option and very affordable. These are setup for MAP sensor based systems as well. They can be found for sale here in shoptalkforums under the Type 1 for sale section.



Dual throttle body setup on Type 1 hybrid engine with overhead cams. This is a slalom race car with high output engine. Note secondary injectors, individual coil packs, and crank trigger setup.



A CIS tuning guide/forum here.

[Longitudinal]

The control current to the meter is set with a potentiometer off a 5V regulator, a couple of resistors for fail-safe current limiting complete the system.

Hello, I just joined this forum because of the above quoted block of text. I have been working with CIS-E for a few years now, and am the owner of the green CIS-E turbo Audi Fox pictured higher up in this thread.

I have been contemplating building my own power module that would be switchable back and forth with the ECU through a pressure switch. I have been using a pressure switch on the CIS-E turbos I build to switch from clsed to open loop under boost, but the DPR current is not high enough to provide the fuel I need for one of the setups I have built.

I assume that what you describe above is controlling current to the DPR (grey box on CIS-E and black on CIS-EM and MB units.) You mention resistors. Is the current track something like this:

power source > 5V regulator > potentiometer > resistor(s) > DPR > ground

What resistance resistors are you using, and are they parallel or series in the circuit? I am very interested in what you have done here, as I have at least two more CIS-E turbo setups to build (one actually for me!) this summer, and DPR adjustment can take me only so far.

[Piledriver]

Welcome to the forums, everyone is welcome, esp if they bring information or ask good questions!

You have it right.

The unit I have is the earlier -50-125mA version from an 85 A4000S, rather than the later +/- 10mA one,(CIS-Motronic?) so it is a bit easier to work with using trivial electronics.

You have to know which you have or you can blow the coil.

A fellow named Miller used to sell a little kit so you could convert an E meter to a high flow basic... I believe it used a fixed orifice in place of the control coil/valve and a CPR or reference pressure of SOME sort was plumbed into the top center of the fuel dist. He used to have a page at dunebuggy.com, but fell off the net a year or so ago.

Speaking from memory, I have 1K pot then a fixed 100ohm as a final to set a max current (fed with 12v, max current is ~100mA if the pot is set at minimum)

When I first set it up to test, I ran it off the trunk light on my 914... Interesting anti-theft interlock...

Also IIRC the coil is 20 ohms.

Adjust resistances as required for 5V... I think I just left the circuit alone and added a 3 terminal 5V reg and 2 1uF caps... it runs best ~23-25mA in any case out of the box, on my engine, YMMV. (It basically runs like CIS basic with a knob on a CPR, just happens to change the current)

I set cold start up on a push button switch in the dash. Bulletproof, use only as needed.

I haven't pushed things with my current setup yet, adjusting the external pressure reg to stiffen the meter would probably be required to get a reasonable calibration at much higher flows. The voltage does NOT seem to change the meter stiffness ala basic and control pressure changes.

I also have a 380SEL meter that I have considered playing with... Possibly grafting the E fuel dist on.
Would look righteous polished, and the cal'd flow range could be extended.

[Longitudinal]

Have you adjusted the DPR? CIS-E responds very well to DPR adjustment, well enough to run pretty well without any current to the DPR. I am thinking that, with some DPR tuning, your little power source could be wired to the WOT switch, the current increased, and used as WOT enrichment.

Of course, this device could be wired in to shunt the ECU under WOT.

I am not sure what you mean by "-50-125ma." But all my stuff is CIS-E, not -EM, so I wouldn't have any problems with that.

I am in the planning stages of a few more CIS-E projects, possibly including converting a motorcycle. Shedding the ECU would be very handy on a motorbike, as space is at a premium and I don't want to go CIS basic and have the CPR in the way. It's bad enough to have a fuel pump and a fuel filter each the size of a 12oz can of soda.