CIS conversion ?s

[you]

thanks piledriver, preciate you suggesting this system to me and the support you have provided along the way..thank you

i was gonna make a short vid for yall but theres two squeals that need addressed...the one i think is a dry dizzy shaft or vac leak, maybe alt/belt or fan...the other was the neighbor two doors up complaining about the "noise"

still far from tuned...i guess itll have to wait till monday

it may appear that an aux air device will be necessary...hard to say at this moment with a potential vac leak on the table...but its a bear to start, prolly due mainly to how its tuned...time will tell

[bradey bunch]

This looks great! any progress?
I am in the middle of making the spacers etc. to try to stuff cis in my 412, and this post is the reason I am trying to do that.

[you]

hey bradey, sorry i havent updated the state of things but lifes been getting in the way....i rearranged some of the plumbing so that now i have an l-jet pump/filter sitting under the cis pump to feed the sump, its a pretty tidy package.....added another 100ohm to the dpr control to keep it in the arena of ~25 mA (may swap to a 3 turn pot as well)...also put an aux air device in, not sure of the need since the tune is currently so bad; but the stupid little caps i was using to cover the ports kept cracking so i figured what the heck, whats one more pair of wires...the squeal was a bad rebuilt alternator.....as it sits now i have it running well enough that i could load it onto the trailer for the move (goin home!)...other than that, rings havent been seated yet and it appears to me that i dont have the airplate/dpr adjusted correctly yet....im not sure if its just a tuning issue or an actual problem with the bmw air sensors venturi (its a bit wonky when using a -basic cone with a -e meter, as the bench setting for the co/"idle mix" screw are so different for the two systems and this is affecting the height of the plate vs plunger et al)....once im settled in the new place ill have time to tinker on it again and will report back with something worthwhile.....best of luck with your build, have fun

[Piledriver]

The basic cone is much shallower than the -E or -M cones, it won't allow full travel.
It's not a battle I would fight... Easy enough to add material to the -E cone if profile changes are absolutely required.

I stuck a -E and then a -M meter in whole and it took about 15 min to tweak in and get 35 MPG and purr again.
(It had a old 77 Scirocco -957 pump, but that's just shy of an -044 pumps specs, so the -M pressure was no problem)

IIRC the only thing that took any time was the cold start line took a different fitting vs, the basic.

You may be making things harder for yourself than needed.

[you]

The basic cone is much shallower than the -E or -M cones, it won't allow full travel.

i havent measured the cones but the spec for the bench setting of the mix adjustment on the -e cone is pretty sloppy (ie tons of free play), which puts the plate pretty far into the venturi before the meter even starts to deliver fuel as i understand it

the metering slits in the -e dizzy are ~5mm (i took one apart)....the -basic cone travel from rest to topped out is ~6mm depending on the co adjustment...should jive, right?

You may be making things harder for yourself than needed.

i believe youre right, but if it just ran ~perfectly/easily i might not bother to learn the nuances...we'll see how it goes, frustration levels might get to the point where i just put the jetta cone in and be done with it (summer is here after all)

[you]

hey all, after a brief hiatus im back to wrenching and anxious to get the engine broke in and tuned....last i worked on it, i had been tweaking the dpr to get the thing running well enough to get on and off the hauler for a move...those settings produced acceptable idle afr but whenever youd get on the pedal it would peg fat really fat (incorrect differential pressure+injector flow rates i believe.....i was also using a -e fd with a -basic air meter, ive since changed to the -e cone set to spec with the dizzy)

so i decided to start fresh and rebalance the fd, set the injector flows, get the dp in the acceptable range, and go from there....in balancing the injectors i managed to get the flow rates way to low (~50cc/min at max meter travel...just an estimate as im spraying into bottles)....ive been doin some fuzzy math and believe ill need in the range of 100-140cc/min but would like to get this dialed in as best i can....

anyone have input as to better values to use for my calcs?....right now im assuming 90-110hp (90s prolly more realistic right?...94x71, rabys 9550, 42x36 heads done by len, vanagon "headers" into a 914 collector, stock 2.0 vanagon intake), .48-.52 bsfc, 55-60 psi at the injectors for cis-e, and 1.0 duty cycle...sound bout right?

once i get the flows right ill play with the differential pressure to see what seems to work statically with keeping the injectors from spitting at 0 meter movement/pumps on while maintaining proper full flow at max meter travel and see if i cant get it to run (right now its at ~5-6psi....and one or two leak a bit, vw says 2.9-7.0 and the mercedes forums say 6.5 seems best-im using a vw fd but mb injectors and dpr)

[you]

little update...after some tedium i managed to balance the injectors to flow at ~110ml/min with a differential pressure of ~6-7psi (it sits at the low side of 6 statically but goes to 7 when injectors are pushin fuel)....fwiw, i was curious to see if the fuel pressure regulator could be used as a load enrichment device..the fpr has a nipple on it to direct fuel elsewhere should the diaphragm break...when you apply vacuum it lowers the fuel pressure however so i thought maybe lower pressure=less fuel (i was hoping i could plumb it to the manifold)...fuel pressure drops ~2psi/5"hg so at 15"hg both system and lower chamber pressure dropped ~6-8 psi and the differential remained constant but no dice...there was no change in fuel flow quantitatively, the quality of flow did however; negatively, with vacuum the injectors sorta pulsed....

as we stand now, im gonna put everything back together, get a good charge on the battery tonight so i can hopefully crank away tomorrow and see how itll run....gettin kinda excited, been far too long since ive driven this thing...update comin soon

[helowrench]

If the fpr has a nipple on it for a hose, you may have an Audi/Volvo/Saab turbo unit.
boost sensing enrichment.

Pull the part numbers off of it.

If it is a turbo fpr, then positive pressure at the nipple will cause the diff pressure to change, moving the curve, and providing enrichment.

Rob

[you]

preciate the input...pretty sure its either vw/audi or a mb unit....i did pull some stuff off volvos/saabs/porsches but that was all -basic stuff iirc and the only things from turboed vehicles i have are a couple wurs i think

never thought to put pressure on it, ill look into it....and who knows, it might run ~right and not even need it...

theres also the option of wiring the air plate potentiometer into my dpr control circuit for full throttle/midrange enrichment, havent really played around with that yet though..or to wire in one of those programmable vacuum switches that piledriver has talked about...but id like to run strictly mechanical if possible though and only use the electricals for cold start/warm up...just waitin on it to get a little later to make some noise, dont want the neighbors mad at me

EDIT: got it running...with the dp set at ~7psi and 110cc/min (right in the middle of mb and vw static settings) it required near constant finger on the 5th injector...i then readjusted the injector flow rates to 120ml/min (vw spec) with similar results...this was the max flow i could set at the lines (one injector ran light, had to balance the others to it)...it ran well with a bit of amperage to the dpr, not sure how much, but the dp was in the ballpark of 12psi...i got a nice lean idle and it would transition rich as i blipped the throttle but then continuing thru enrichment to the point of the wbo2 not being able to measure as rpms rose...seems the plate is rising too quickly er i need to toy with the other mixture screw in conjunction with the dpr set screw and idle air more....right now im taking the time to clean up a few other fuel dizzys(one im running allows a little fuel out an injector, and have a spare thats already setup) and get the volvo meter plate tapped for the -e dizzy....after that i may consider putting a small spring above the plunger like mercedes does

[you]

i believe its update and beg advise time...after mucho toying around with different cones and adjustments here and there i believe its all for naught..well sorta anyways...it would appear that my wbo2 isnt functioning properly...maybe its the sensor er maybe the jaw unit itself, im not sure but i dont trust it.....the vans running and as of today inspected so i can actually do some drving around while trying to tune this thing....the problem lies in that im not much of a tuner...so any advise on tuning by ear would be greatly appreciated...

heres where im at:
when i free air calibrate the jaw it gives me values in the range of -5 to -2 more or less....so ive been keeping it at around -3 or -4...when i tune in the driveway to get an afr around 13ish it drives fine and ill get a lean miss at 17 or 18 afr if things arent tweaked correctly(idle afr on overrun), so that all makes sense...however there is the occassion when it reads 34.xx (lean) when i know its actually rich....so ignoring the gauge, i played with the fueling at idle and 3k to a point where it seems in the middle of rpms dropping off and it sounds good and strong( more fuel than previously idictated by the gauge)...with it like this the afr reads 34...i got curious how this would be affected by the calibration value and sure enough with it set to -25 the afr read 13.5 er so at both rpms...so do i trust my ear, the gauge, neither...i ran out of time today and will prolly draw more conclusions as i drive it around tomorrow, i was just wondering if others have had similar issues or could correlate afr to ear(ie as fuel is added, the start of rpms rising is 14 and the falling off is 9 and so on)...preciate it all

[Piledriver]

My JAW 1.03 always worked great, even after a bad voltage regulator blew it out violently (needed traces replaced)

I replaced mine with a SLC-OEM eval kit, read ~exactly the same on the same tune.
(My JAW still works)

OTOH I got the JAW used/not working and had to rework a few bad solder joints.

The only thing that kicked my butt with it was the hole for the sensor into the tailpipe was not cut quite big enough and it lied to me for a long time... sensor body was just touching, a thermal short, read a little>a lot rich all the time.

If it's reading free air like that, how close are you to the tailpipe? Any ex leaks?

The free air cal only really has any effect on the lean side of stoich.

Consider the CO screw zero, the DPR as span, either by twerking the zero screw or feeding it current.
Between the two adjustments you should be able to get a decent running (if a tad rich) tune in < 10 minutes once you can put a load on it... (There is precious little else to adjust with a -E or -M meter)

If you stay with the CIS, and decide to upgrade the WB, consider on of the SLCs with logging capability.
The top end one even has sdcard logging.

[you]

thanks for the input pile...im running the 1.041 unit, so i can log it but the rpm input wont work for me....i never really had problems with it till now, when first installed on an ljet motor (before it blew) it read exactly as you would expect...part of me thinks i soiled the sensor during initial run-in and getting the fueling dialed in...ive been reading about sensor cleaning, but im wary of destroying it in the process when that might not be the problem...that and i have my doubts about cleaning actually doin anything....alan gave me a naw unit when he was experiencing shipping delays with the jaw boards..i think he also wanted some beta testers...so i could use that to verify but means i would need to get soldering and i have little time to get the van on the road.....regarding the free air claibrate, it sits just after the collector so i just pulled the muffler to do it because i couldnt get it to budge from the bung...i got similar values as when i first bench tested the unit....-4 gets me 14.9 with no sensor attached so it all seems fine, i just get squirrelly readings from time to time (max lean, which it reads when its way rich for some reason)....the plan now is to see what i can do abouta firmware update once i figure out the .net issues im having with the software (i mistakenly reinstalled it after i had updated windows)....other than that i think ill give the engine what it seems to want and watch the head temps i guess

[Jadewombat]

Pictures would really help here...

[you]

what would you like to see wombat?

after a firmware update, some miles, and fresh gas things seems to be progressing...the engines loosening up a bit and the wb is behaving better...i believe im getting the tune dialed in too...the only issue currently is that ill set my fueling, drive it a bit and will be fine going down the road at around 12.5-14, ill hit a grade and electrically add more gas so that its around 12 or 13 under load, which it likes but then in the flats it will read 34 (too rich) and wont lean out after electrically reducing fueling to baseline...i have to go back and manually lean out the dpr....its strange....im seriously considering an smc vaccum switch for dealing with load enrichment...i didnt want to add anymore electricals than necessary but now it would seem would be a great benefit...plus it would be a good diagnostic tool and an additional "warning light"....or maybe tie the dpr control module into a wot switch....

[Piledriver]

An SMC programmable vacuum switch would be a win, and allow you to lean out things at light load considerably.
They will run off 12v.

Caution:If you lean things out significantly you will probably need more timing there..
Probably not a show stopper, but that's how I got my CHTs down significantly.

I'm just about to put my 86 Cabriolet back on the road, I'll probably be looking at controlling the CIS+Lambda with MS2-extra if only for the ignition control.