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

[gurov]

you should have seen it retarding timing in the log if it was the launch i would have thought??

that didn't happen, final timing looks correct in the log, but MSQ says launch is on, and on at 4500 rpm.

unless there's an update, in which case i apologize.

[vw_chuck]

Do you have an oscope? Put a current probe on the power lines to the injectors and coils and see what is gong on. You will see if the coils are not firing and same goes for the injectors.

[JoseMiguel]

is your launch control by any chance on ? it's enabled at 4500 rpm, if your launch_in is triggered on at all times ?

I thought the same at first but no, it is not on, and just for the peace of mind, it is completely disabled

not in the MSQ that was attached earlier.



good if it's disabled now.

yes, the current MSQ has launch completely disabled!

[JoseMiguel]

We did everything one can think of, everything has been triple checked...

Im starting to think I have faulty quad spark modules, or a faulty MS3... I have ran through all the possible diagnostics and I cant find where else to look.

I know that BIP373 are strong, and I have yet to see one of them damaged, but nothing else makes sense. I am an experienced MS'er and all the tricks and whistles I have learned throughout the years are useless with this car!

MS3 has spark test mode. test the coils at well above 4500 rpm to see if they light up a spark.

can you rev past 4500 without boost ?

if I drive the car trying not to let it go above 3-4 psi, it reaches the rev limiter without problems. It also reaches the rev limiter if I rev it in neutral.

[JoseMiguel]

After practically re-wiring the whole car, I think we found the problem, and is as stupid as ever...

to make things neater, we used connectors in all the cables, including the quad-spark grounding. Unfortunately, we found that the quad-spark connector was not crimped correctly and it made false contact with the ground!

the light of hope shines ahead! im crossing my fingers here

[grom_e30]

hope that does it.

[gurov]

After practically re-wiring the whole car, I think we found the problem, and is as stupid as ever...

to make things neater, we used connectors in all the cables, including the quad-spark grounding. Unfortunately, we found that the quad-spark connector was not crimped correctly and it made false contact with the ground!

the light of hope shines ahead! im crossing my fingers here

that totally doesn't sound like the fix or the issue, if you can get it to revlimit just fine offboost, on-boost death must be boost-related, and fuel related. your dwell is static, so boost 6000 rpm or no boost 6000 rpm should be same.
unless it's misfires if the coils can't deliver a proper spark.

what are the plugs gapped at ?

[JoseMiguel]

BINGO!!!!! finally, we made it...

the quadspark grounding solved part of the problem, but the real problem was even more stupid: MS3X grounds were connected to a bolt in the chassis and its grounding "power" was poor. I took the grounds and connected them directly to the block and problem solved.

"the easiest explanation is usually the right one"

thanks to all the people that came here to help, no matter if you were right or wrong, I really appreciate it.

[gurov]

there has to be a better electrical explanation than "bad ground" though.

glad you got it solved though.

as you see from the sig, i've got an E46 325xi, but i'm quite a bit less gentle to the stock things, and i'm running a topmount.