car stalls out

[BADCLOWN]

e30 w/ m52, euro maf, OBDI, red label



the car tends to idle ever so slightly off normal idle, when i come to a stop on occasion the car has just sputtered and died but sometimes it when i come to a stop and then try to start in 1st gear and give it gas, the car wont have any power, boggs down, sputters and dies quickly.



- fuel pressure is good
- vacuum is fine
- plugs dont look fouled




any insight? it doesnt shut down every single time i come to a stop but in my 15 minute drive to work it did so 2-3 times (i come to a complete stop 9-10 times during my trip to and from work) but the ever so slight difference in idle is noticeable constantly for the most part and slightly rough in nature

[RUFFLZ]

clean le icv.

[greyis89]

Check icv. Make sure the maf and the main relay is good.

[328ijunkie]

what tune?

[BADCLOWN]

what tune?

no aftermarket tune. red label only.

[328ijunkie]

And you expect it to run right?
That factory chip is made for a 3" MAF, 19lb injectors, 2.5L motor etc.
Surprised you havent blown it up yet.

[BADCLOWN]

And you expect it to run right?
That factory chip is made for a 3" MAF, 19lb injectors, 2.5L motor etc.
Surprised you havent blown it up yet.

its been running perfectly normal. from my understanding and research you can run the red label you just dont get the optimum performance out of it/most people add on to that ecu by chipping it, running the euro maf, and doing injectors. the car just isnt performing optimally or utilizing what that ecu has to offer.



regardless, it seems to be boiling down to a bad maf, going to grab another 3.5 inch as well as an OE m52 maf to test and see what turns up.

[BADCLOWN]

double post

[328ijunkie]

M52 maf wont even plug in and do you not get that youre running a M52 on smaller injectors it was designed for, a random MAF which it isnt tuned for thus your AF raitos are all Fed because the MAF isnt scaled to the ECU properly, and a tune for a 2.5L displacement engine which despite what you may think changes things alot.

And i dont know where youre getting your research from but i know of no one running an M52 the way you are. It is a KNOWN fact that you need a tune for a M52 or S52 to run it OBD1. Thus why every tuner out there makes such tunes to make the engine run and operate properly at the very least.


I dont get how people understand they just cant change shit around without letting the ECU know what the hell is going on.

Injectors, MAF, etc are all HARD coded into the chip. The chip is basing its tuning maps off the set injector constant and set MAF constant. So running a 3.5" maf in place of a 3" without tuning will DRASTICALLY mess with the performance and tuning of the car. The ECU is going to be confused as hell as whats going on as its seeing X air come in through the MAF injecting X Fuel and expecting to see X A/F ratio at the O2 sensor.