strange fueling behavior... BMW 325i E36 + MS3

[JoseMiguel]

spark blow out maybe causing it to read lean?

that was my first thought and it is what im first aiming for... spark blowout

what seems strange thought is that supposedly, this COP's are strong as hell and they will support big hp numbers from what I have seen around. This are wired to the MS3X using quadspark modules which have always given a hot spark from what I have seen before...

I also tried a few sets of spark plugs and different gaps but no luck. Right now im running NGK BKR7 resistor plugs...

what Im planning to do now is try a Ford 6 cylinder coil (wasted spark) and see what happens... but im having trouble finding the coil...

[grom_e30]

i think i have seen arguments both ways on the coils, you have gapped the plugs down pretty tight i take it.

[JoseMiguel]

i think i have seen arguments both ways on the coils, you have gapped the plugs down pretty tight i take it.

I have gapped them to the point that it is hard to get it started!

Maybe im just running in circles here and the problem is simply, weak coils. But this have to be the master of weak coils not to be able to support a few pounds of boost...

[grom_e30]

can you maybe borrow a set off someone to test the theory? also have you ohm metered the coils to see if they meet the service specifications? could be 1 or 2 coils weak miss firing pumping unburnt air through exhaust and you know the rest.

[JoseMiguel]

can you maybe borrow a set off someone to test the theory? also have you ohm metered the coils to see if they meet the service specifications? could be 1 or 2 coils weak miss firing pumping unburnt air through exhaust and you know the rest.

It would be hard to find someone kind enough to borrow me the same coils, so im going to do the test with a ford coil pack which I have used before for high HP applications and works well.

Do you have the service specs for this coils? what should they read with the ohmmeter?

[grom_e30]

coil primary between pin's 1 and 15 0.4-0.8 ohm according to bentley.

[93supercoupe]

I just figured mine out. It was an ignition setting. It was the setting that suggests that if you select wrong, the timing will wonder.

Not to de rail- but do either of you know the calibrations settings for the m50 clt and mat? I can't find them

[JoseMiguel]

coil primary between pin's 1 and 15 0.4-0.8 ohm according to bentley.

1 and 15 would be signal and ground right?

[nuvolarossa]

1 is ground, 15 is signal. should be 0.4 - 0.8 ohms.
Here is pinout/values from service manual http://i178.photobucket.com/albums/w257 ... esting.jpg

The log shows 14.7 AFR in there but im guessing it is some kind of limitation with the logging of this WB module (the display shows 18...20AFR in there), but you get the idea...

Yeah to me it seems spark blowout/misfire too. Dwell is correct in this log.
Which wideband module are you using? It's not normal that on gauge it shows 18-20 and on log only 15...
call me crazy but it's weird how your afr pegged perfectly at 12.2-12.1 everytime. I have a feel you are too rich and the afr is indicating wrong?

- the wideband calibration (volt vs afr) in tunerstudio is correct? double check this.

Also you have lag factors in general settings very low (your MAP lag is at 25). Try to raise them all to 90-100 (100 is unfiltered) for next logs, also for afr, just to see if the averaging is hiding something.


EDIT: are you sure you haven't wired the coil reversed? I mean inverting + and -? I don't know what would happen, never tried

[JoseMiguel]

1 is ground, 15 is signal. should be 0.4 - 0.8 ohms.
Here is pinout/values from service manual http://i178.photobucket.com/albums/w257 ... esting.jpg

The log shows 14.7 AFR in there but im guessing it is some kind of limitation with the logging of this WB module (the display shows 18...20AFR in there), but you get the idea...

Yeah to me it seems spark blowout/misfire too. Dwell is correct in this log.
Which wideband module are you using? It's not normal that on gauge it shows 18-20 and on log only 15...
call me crazy but it's weird how your afr pegged perfectly at 12.2-12.1 everytime. I have a feel you are too rich and the afr is indicating wrong?

- the wideband calibration (volt vs afr) in tunerstudio is correct? double check this.

Also you have lag factors in general settings very low (your MAP lag is at 25). Try to raise them all to 90-100 (100 is unfiltered) for next logs, also for afr, just to see if the averaging is hiding something.


EDIT: are you sure you haven't wired the coil reversed? I mean inverting + and -? I don't know what would happen, never tried

Thanks for the answer

I usually like a low lag value for wideband and that is probably the reason why it seems so "perfect". The reason is that low lag helps avoiding "hunting" when using ego correccion (ego correction is off in this car). I also tried rpm and map lag values in 100 to see if I was missing something, but no luck.

The wideband used in this log is a diy wbo2 and it is well calibrated (same reading on the diaplay and tunerstudio) but wont show values over 15 in ts which is strange indeed. The day I made the log I only had that wideband avaliable but I usually use a AEM. In this car I already tried my aem, the diy and a brand new afx powerdex. They all show the same.

I tested one of the coils and how dwell affects it with a plug outside the car using the test mode. Below 1 spark is barely seen. Around 1.5 it starts to glow strong. Around 2.5 seems to be the strongest spark, blue, thick and noisy. Around 3.5 it starts to turn yellowish. At 4.5 it is more yellow than blue...

[JoseMiguel]

EDIT: are you sure you haven't wired the coil reversed? I mean inverting + and -? I don't know what would happen, never tried

I think I found something, and if it is this is going to be the most stupid problem ever...

When we wired the coils, we checked with a multimeter and a test light what pin did what. We found 12v in the leftmost pin, ground in the center and signal in the rightmost and that is how it is wired...

[JoseMiguel]

EDIT: are you sure you haven't wired the coil reversed? I mean inverting + and -? I don't know what would happen, never tried

I think I found something, and if it is this is going to be the most stupid problem ever...

When we wired the coils, we checked with a multimeter and a test light what pin did what. We found 12v in the leftmost pin, ground in the center and signal in the rightmost and that is how it is wired...

Let me rephrase... The diagram is showing the plug and not the coil

I have 12v correct but signal and ground are inverted...

If this works, im going to pull my hair off and throw from a cliff!!!!

[nuvolarossa]

go here http://wedophones.com/Manuals/BMW/
find your manual.
read it, there are schemes and pinouts.

for some years wire colors at coils was:
green is power.
black is signal. (quadspark)
brown is ground.

EDiT: yeah I know those are plugs diagrams, it tricked me too a few times. (not on coils )

rewire those, use 2.7-2.8 dwell, and go burning tyres. after you fix that, post working log for curiosity

[JoseMiguel]

go here http://wedophones.com/Manuals/BMW/
find your manual.
read it, there are schemes and pinouts.

for some years wire colors at coils was:
green is power.
black is signal. (quadspark)
brown is ground.

EDiT: yeah I know those are plugs diagrams, it tricked me too a few times. (not on coils )

rewire those, use 2.7-2.8 dwell, and go burning tyres. after you fix that, post working log for curiosity

Ill do, thanks for all

The question now is, why is it working (and works well until boost comes hard) with those cables inverted?

My reasoning would be that since signal is grounded all the time, when the quadspark grounds the real ground, it works

Btw, I have those cables with those colors which also confirms this even further and yes, they are inverted!!!!!!!

[93supercoupe]

just a fyi, the underside of the coils will also be labeled 15/40/1. You have to turn the coil upside down to see the labels.

[nuvolarossa]

First try if it works good after rewiring them and that nothing got damaged (quadspark/coils), then we'll discuss about this (I have to think a bit about it and look a couple of diagrams )

[JoseMiguel]

just a fyi, the underside of the coils will also be labeled 15/40/1. You have to turn the coil upside down to see the labels.

Yes they do!!!!

[juansh2385]

Jose this happen to me before around 8 psi in my case it was the engine. The head gasket leaked water to the cilinder when boost past a certain limit affecting the wb reading ( my was innovate wb and it read 22 afr) when the problem happened.

I am not saying that your problem is the same because I know is not and easy fix and I dont want you to jump to conclusions but in my case that was my problem.

Juan

[gurov]

what injectors are these ? any way you can throw much larger injectors into this thing ? duty cycle goes pretty high up.

i once had a crazy issue like this in the supra, turned out to be a dirty fuel filter, and the injectors were large enough to cause a pressure drop at the rail.

[JoseMiguel]

what injectors are these ? any way you can throw much larger injectors into this thing ? duty cycle goes pretty high up.

i once had a crazy issue like this in the supra, turned out to be a dirty fuel filter, and the injectors were large enough to cause a pressure drop at the rail.

Yes, I tried many sets of injectors, these are the smallest we had for testing

But I think we found the problem as documented in the last few threads. Tomorrow morning im re wiring the coils and see what happens!