T3 megasquirt II conversion

[akokarski]

Hi Guys,

I've been reading, searching for a few days on possibility of converting T3 FI motor to megasquirt. It almost looks too simple and makes me think I am probably missing something, hence this post...

I know there are quite a few folks here who is running MS with stock beetle injection hardware. Out of all conversions this seems like fairly straight process as most of the hardware is already in place. Fuel pump is there so are return lines and fpr. No messing with intake manifolds, throttle body and injectors. It's almost a PnP conversion except for a few hardware bits. And could look pretty close to stock except for a few giveaways such as wiring harness, IAC

Following sensors seem to require the biggest fabrication of the conversion:

1) O2 sensor (Bosch LSU4 ) http://wbo2.com/lsu/
Where to place o2 is where I have my doubts. Putting it in tail pipe is probably too far down stream, it won't get hot enough and can probably suck in fresh air. So far I've been thinking about putting into side of the muffler, but not sure if it will get enough flow.

2) IAT - GM Unit per MS manual
Thinking of placing in the bottom of the stock throttle body. There is not enough of room on the sides to have enough space for the hole and be able to screw it in.

I can mill off boss with two fittings and either drill and tap bottom directly on the body or attach aluminum adapter block with angle for the sensor so that connector points toward 3/4 side and down. This way sensor is hidden and I can isolate from heat soak using phenolic spacer.

Is there another sensor with 8mm thread that can be used in a stock location above 3/4 runners, or could I just use Bosch 0 280 130 014 ? http://www.carpartsdiscount.com/auto/pa ... 3593=52174

3) CLT - GM Unit per MS manual
In valve cover on 1/2 side.

hardware that doesn't really require modifications or fabrication.
4) IAC or Fast Idle Solenoid
Here I can simply use Bosch electric AAR (I actually have two of those and mounting bracket) Or just leave Stock mechanical AAR.

5) TPS Bosch 0 280 122 001 http://apps.bosch.com.au/motorsport/dow ... sition.pdf
This guy has almost the same profile as stock TVS and a "D" Drive type! The only problem I can see with it is connector receptacle being too close to #2 runner.

6) Ignition
Planing on locking out distributor and bosch 124 to fire coil http://www.megamanual.com/ms2/Bosch_124.htm

7) Injectors, will be using stock, but I want to find non D-Jet connectors, I haven't figured this one out. Is there a later part number that I can reference? Or can I simply use ev1?

Which leaves us with ECU, relay board and harness.
Given that I wouldn't even attempt to solder pcb boards myself, (I don't have steady hands, and really good eyes. ) I would opt in to buy assembled MS, would I need to get stim? It's already assembled, I shouldn't need to test it...

Could I just use microsquirt mounted in place of stock ecu? I could hide MAP sensor in gutted up bad MPS.

With MicroSquirt should I still get relay board? or will it be enough to drive stock injectors? If I do have to get a relay board maybe i can hide it in charcoal canister

MicroSquirt looks more appealing then Megasquirt as I don't have to hide it under back seat (little bit concerned being close to heater bellows. And it can sit where original ecu used to be.

I know this is a bit much of reading here, but I want to get a sanity check, since I always miss some important detail.

Thanks,
Anton

[1955cc66bug]

Just wondering...why would you want to do megasquirt to an already EFI'd motor that I assume runs good? Not knockin ya, really just curious.

[akokarski]

It runs good whenever it wants. Trying to figure out what is wrong with it has proven itself very cost ineffective. Just trying to save this car from being sold, going to junk yard etc. Also in the future it will probably get a little bigger motor. Besides why do people swap stock ECUs on other cars?

[1955cc66bug]

Gotcha dude....like I said, just wondering.

[raygreenwood]

It runs good whenever it wants. Trying to figure out what is wrong with it has proven itself very cost ineffective. Just trying to save this car from being sold, going to junk yard etc. Also in the future it will probably get a little bigger motor. Besides why do people swap stock ECUs on other cars?

Then come over to the type 3 forum or maybe even ask right here about how to fix it. D-jet is phenomenally dependable....but its very tedious to adjust properly. It tolerates "0" vacuum leaks....must have rock solid stable fuel pressure ...and the stock harness was crap. MS is pretty cool....but if you are looking for a stock runner and your D-jet compoents are in good shape, build a new harness ($150 approx.) and then tune it correctly. If that is not enough at that point...then you still have a good start for MS. Also...learning to tune D-jet will provide revelations about injection issues in general. Ray

[miniman82]

Totally agree. If you have a bum harness that's causing you issues now, adding MS to the equation will only make diagnosis harder. Try to find the problem, them if you get totally fed up, put MS in.

[akokarski]

I totally hear you guys on sorting out D-Jet. Problem is that issues that I've been having with FI are not consistent. I've been through vacuum leaks, all new seals, gaskets and hoses. Also all brand new ignition. I've taken it to three very knowledgeable mechanics, and it does run a bit better while they have it. Once I pick it up it's all good old story of missfiring and jerking. So far had MPS swapped, old one didn't hold vac. tried 3 different TVSs. Problem is that I could spend hours and it would seem better. Next day some new fit, or similar fit just in different order. It is some electrical issue and I can't really hang out the back trying to find it while driving.

I've been through it with bosch tester and everything checked out ok. Simply I cannot afford trying to sort this out, really have no time to invest into trouble shooting it. There are other projects I would rather work on and have this car on the road.

Now with MS it is a fresh start. Any modifications that are needed to stock parts are going to be done on spares, so I would still have a way to go back if it comes to that. The only things that in question that are going into this conversion are injectors. I have a spare set that I can send out for a rebuild. At that point everything is brand new!

If this conversion can be done there is at least one more car that will get converted from carbs to FI! And I can use this experience when I inject my beetle as well.

wrenching is fun, but at some point you gotta get driving.

Oh and with MS I would not be using stock harness either. Unplug the old and go with the new.

Thanks,
Anton

[Devastator]

1) O2 sensor (Bosch LSU4 ) http://wbo2.com/lsu/
Where to place o2 is where I have my doubts. Putting it in tail pipe is probably too far down stream, it won't get hot enough and can probably suck in fresh air. So far I've been thinking about putting into side of the muffler, but not sure if it will get enough flow.

Mount it after the collector(s) and before the muffler.

2) IAT - GM Unit per MS manual
Thinking of placing in the bottom of the stock throttle body.

Just about anyplace in the intake, that keeps it away from heatsoak, should be fine. If you plan to run a turbo someday, however, it should be after the turbo and not before, (like mine).

3) CLT - GM Unit per MS manual
In valve cover on 1/2 side.

Should be fine.

4) IAC or Fast Idle Solenoid
Here I can simply use Bosch electric AAR (I actually have two of those and mounting bracket) Or just leave Stock mechanical AAR.

I don't know squat about the stock AAR, sorry.

5) TPS Bosch 0 280 122 001 http://apps.bosch.com.au/motorsport/dow ... sition.pdf
This guy has almost the same profile as stock TVS and a "D" Drive type! The only problem I can see with it is connector receptacle being too close to #2 runner.

If you can make it work mechanically, MS should be able use it.

6) Ignition
Planing on locking out distributor and bosch 124 to fire coil http://www.megamanual.com/ms2/Bosch_124.htm

MS will trigger from points, although I suggest using something else. A VR sensor and trigger wheel at best, or a Pertronix module in the locked dizzy at worst.

Injectors, will be using stock, but I want to find non D-Jet connectors, I haven't figured this one out. Is there a later part number that I can reference? Or can I simply use ev1?

Sorry, I don't know squat about these injectors either. You could ask on the MS forums if you can't get an answer here.

I would opt in to buy assembled MS, would I need to get stim? It's already assembled, I shouldn't need to test it...

You don't need the stim to make MS work but it is hard to find a board problem without it. I don't have one, but my board was assembled and tested with one.

Could I just use microsquirt mounted in place of stock ecu? I could hide MAP sensor in gutted up bad MPS.

Much of the rest of your post suggests hiding your MS2, (or Microsquirt). With MS2 you have abuilt in MAP sensor and you can simply use relays instead of a relay board, (the board just makes it easier and, sometimes, cleaner). If you want to hide the MS controller, it's not difficult to do and there would not be a MAP sensor to hide, only a vacuum line running to your hiding spot with a bunch of wires. I forget what options you lose with Microsquirt, but I remember that it was designed more for motorcycle sized engines, so I'd suggest the MS2. Either will work. Just my 2c.

[akokarski]

thank you Devastator!

1) O2 sensor (Bosch LSU4 ) http://wbo2.com/lsu/
Where to place o2 is where I have my doubts. Putting it in tail pipe is probably too far down stream, it won't get hot enough and can probably suck in fresh air. So far I've been thinking about putting into side of the muffler, but not sure if it will get enough flow.

Mount it after the collector(s) and before the muffler.

I was hoping to keep stock muffler and not have to jump to OTT. I've searched and searched, but cannot find anybody running o2 in a stock muffler.

I did see this http://www.thesamba.com/vw/classifieds/ ... ?id=802629

2) IAT - GM Unit per MS manual
Thinking of placing in the bottom of the stock throttle body.

Just about anyplace in the intake, that keeps it away from heatsoak, should be fine. If you plan to run a turbo someday, however, it should be after the turbo and not before, (like mine).

3) CLT - GM Unit per MS manual
In valve cover on 1/2 side.

Should be fine.

4) IAC or Fast Idle Solenoid
Here I can simply use Bosch electric AAR (I actually have two of those and mounting bracket) Or just leave Stock mechanical AAR.

I don't know squat about the stock AAR, sorry.

5) TPS Bosch 0 280 122 001 http://apps.bosch.com.au/motorsport/dow ... sition.pdf
This guy has almost the same profile as stock TVS and a "D" Drive type! The only problem I can see with it is connector receptacle being too close to #2 runner.

If you can make it work mechanically, MS should be able use it.

6) Ignition
Planing on locking out distributor and bosch 124 to fire coil http://www.megamanual.com/ms2/Bosch_124.htm

MS will trigger from points, although I suggest using something else. A VR sensor and trigger wheel at best, or a Pertronix module in the locked dizzy at worst.

Pertronix sounds good.

Injectors, will be using stock, but I want to find non D-Jet connectors, I haven't figured this one out. Is there a later part number that I can reference? Or can I simply use ev1?

Sorry, I don't know squat about these injectors either. You could ask on the MS forums if you can't get an answer here.

I would opt in to buy assembled MS, would I need to get stim? It's already assembled, I shouldn't need to test it...

You don't need the stim to make MS work but it is hard to find a board problem without it. I don't have one, but my board was assembled and tested with one.

Could I just use microsquirt mounted in place of stock ecu? I could hide MAP sensor in gutted up bad MPS.

Much of the rest of your post suggests hiding your MS2, (or Microsquirt). With MS2 you have abuilt in MAP sensor and you can simply use relays instead of a relay board, (the board just makes it easier and, sometimes, cleaner). If you want to hide the MS controller, it's not difficult to do and there would not be a MAP sensor to hide, only a vacuum line running to your hiding spot with a bunch of wires. I forget what options you lose with Microsquirt, but I remember that it was designed more for motorcycle sized engines, so I'd suggest the MS2. Either will work. Just my 2c.

I think I will stick with megasquirt and relay board. ms will go under the back seat.

[raygreenwood]

I totally hear you guys on sorting out D-Jet. Problem is that issues that I've been having with FI are not consistent. I've been through vacuum leaks, all new seals, gaskets and hoses. Also all brand new ignition. I've taken it to three very knowledgeable mechanics, and it does run a bit better while they have it. Once I pick it up it's all good old story of missfiring and jerking. So far had MPS swapped, old one didn't hold vac. tried 3 different TVSs. Problem is that I could spend hours and it would seem better. Next day some new fit, or similar fit just in different order. It is some electrical issue and I can't really hang out the back trying to find it while driving.

I've been through it with bosch tester and everything checked out ok. Simply I cannot afford trying to sort this out, really have no time to invest into trouble shooting it. There are other projects I would rather work on and have this car on the road.

Now with MS it is a fresh start. Any modifications that are needed to stock parts are going to be done on spares, so I would still have a way to go back if it comes to that. The only things that in question that are going into this conversion are injectors. I have a spare set that I can send out for a rebuild. At that point everything is brand new!

If this conversion can be done there is at least one more car that will get converted from carbs to FI! And I can use this experience when I inject my beetle as well.

wrenching is fun, but at some point you gotta get driving.

Oh and with MS I would not be using stock harness either. Unplug the old and go with the new.

Thanks,
Anton

(1) The number of mechanics shops in this country who can sort your D-jet out for you can be counted on one hand...maybe two. Most of these peopel are not running shops either.
(2) there are no books ever printed that tell you how to do the proper adjustments on D-jet for the MPS....so unless these people are long time experts....they have no business practicing on your system...which I can all but guarantee you...they are.
(3) Its a no-no swapping parts..especially the MPS. Draw a vacuum on it. If it holds vacuum and then a simple resistance check of the two pair of contacts matches book...then there is nothing wrong with it and it simply "might" need adjustment.
(4) just unplugging components on old D-jet harnesses is enough to change the running.


(5) the MPS has nothing whatsoever to do with the "chugging" or "bucking" syndrome with D-jet
(6) the Bosch tester is worthless. It depends 100% on the integrity of the wiring harness...which becomes defective with age.
a simple digital voltmeter and an accurate fuel pressure gauge can tell you everything you require in 20 minutes

Quit swapping parts!!!!! How did you ADJUST the TVS? Virtually all of the books have incorrect adjustment procedures for late model TVS...and...not one publication ever has information about how to verify adjustment after adjusting.

Ask for some help and we will help you. And yes...I do have a Bosch cert for D-jet from long ago. It is actually worthless compared to what I learned by tuning and driving. The publications and info on this system are thin..because it was only used for about 8 years....and during those 8 years it was deemed that all adjustments were beyond anyone but compenet factory technical personnel. They just swapped parts at the dealer. As soon as L-jet came out and the dealers were absolved...they just dumped all technical information aside.

And no...the Probst book will not help you with anything other than theory. Seriously....ask a few questions and tell me what your readings on variosu parts are...and I (and others) can help you. Ray

[akokarski]

Hi Ray,

I've tried this on samba, but I guess I could give it try again, no harm just time. Should I open up a new thread in t3 forum?

Also about that bung for o2 sensor in the muffler, can I do this? I do have a wide band that might help either now or later on regardless of whether or not I convert to MS.

Thanks!
Anton

[raygreenwood]

I would suggest keeping it here if you want because this is a really good forum...or also you could make a note to see this post in the 411/412 forum on the STF.

I love the Samba....but there are a few more people watching over there who really only answer for good conversation...whether they can help you or not. It tends to get a little too cluttered up.
But....if you post over in the D-jet for experts sticky...and stick with it.....the best people on that forum (which are also many of the same ones here) will help you.

By the way...I'm not beating on you. You are working this out just fine. MS is a good thing to explore.

What kind of muffler are you using? Stock mufflers for type 3 and 4 are difficult to get a good site for an 02 sensor because they can have a tendency to sample only one bank of cylinders or even one cylinder. Type 3 stock is better than type 4. Ray

[akokarski]

Hi Ray,

I believe it is T3 muffler, but I am not absolutely positively sure as it never occurred to me that it could be a T4. I will take some pics to ID.

If I were to start a troubleshooting thread I want to keep it on stf. Should I post in "Fuel Injection" Forum or "Type 3 Forum". This way we can keep MS conversion separate from D-Jet.

Thanks again,
Anton

[raygreenwood]

Keep it in this forum or in ....believe it or not....the 411/412 forum. There are a small handful of parts differences that are type 3 D-jet only. These will usually not be the issue unless its a hard to find part that is the culprit. In odd type 3 detail cases...Russ in the type 3 forum on Samba is an excellent source.
But for D-jet troubleshooting, those who frequent the 411/412 forums and here are pretty good...if not excellent.

So start a thread and tell us what happened, when it started and what all you have done...from the top. It may get long....and thats no problem. Those who are not interested in D-jet will simply skip it.
D-jet tuning work on line will always be long winded. There is much to explain and not that much in books.

But....the D-jet sticky on the Samba is a"decent" place to familiarize yourself with the system. Just do not get caught up in all of the answers. Several of the peopel postting there really know alot about D-jet....but the vast majority either do not know much...or are 100% hung up in the sparse factory literature and doing exactly everything VW susggested...which by the way included no MpS tuning and nothing other than rudimentry troubleshooting.

By the book....the only adjustments are idle, TVS and timing. This is actually untrue. Ray

[akokarski]

Ok posted in 411/412 http://shoptalkforums.com/viewtopic.php?f=12&t=132887