tuned car running lean under part throttle (no kiddy question)
 

Hallo,

i need some help, i have a car here that is well tuned and runs great. but sometimes we have the problem (most when it is cold and wet outside) that from one moment to another the wideband shows that the car runs extrem lean under part throttle.

the mixture jumps from 14.7:1 to 16:1 or sometimes 17:1

the closedloop is disabled and the maps are not the problem because normaly the mixture is overall 14.7:1 in part throttle till 650-700mbar after that is has 13.5:1 and a bit richer under boost.

if the problem accures the mixture goes to 17:1 in part throttle, 14.5:1 at about 1000mbar and low 14:1s under boost (we don't check the last one for a long time not to harm the engine)

the EMS is something like uberdata, but itself is not the problem because runs fine in another car. So the problem must be in the car itself.

What sensor or hardware failure can cause a lean condition over a longer period?

oh i forgot, full throttle overcomes the symptoms, but only full throttle, boost alone with part throttle at high rpms has the mixture problem.

what i can figure out is that the tps voltage is very low (aprox. 0,2-0,3v at closed Throttle)

the engine is a B16A1 engine.

has anyone ideas? i don't know more at the moment... please help us with suggestions... even stuipd one's so that we have something to check ;-)

Thanks
Malte.

Re:tuned car running lean under part throttle (no kiddy question)
 

TPS, IAT, Water Temp, O2 & MAP sensor are the only ones that affect AFRs.

Gotta be something to do with them.

Be more specific with what EM it is, the fact that you are being secretive leads me to wonder...it may be something you are unaware about that someone may have better answers.

Re:tuned car running lean under part throttle (no kiddy question)
 

Hi,

sorry that i don't have posted more informations about the EM, but it is not because i don't want to tell you, but i think it has nothing to do with itself.

it is a changed software for the euro pw0 ecu, based on a file i got from a budy (can't tell the name here in public) from new zealand.
but it is basicaly only an advanced fuel & ign tables so that the stock software can run with boost. Just think you have bigger tables and the rest is stock PW0 code.

But if i'am informed right, water temp only can enrich the fuel trim? MAP Voltage is normal, O2 is disabled so don't effect, IAT?! don't know but datalogging shows a normal input voltage, TPS? big ??? voltage is very low at closed throttle, datalog shows normal readings, just a bit low but thats all...

maybe some kind of vacuum leak? that leans the mixture out?


Thanks
Malte.

Re:tuned car running lean under part throttle (no kiddy question)
 

i have the answer, but it's g14 classified ::)

Re:tuned car running lean under part throttle (no kiddy question)
 

Seriously, PW0/PR3 code is something everyone is interested in and would like to know more about.

This is a public forum and we are here to share and help each other out. If you want to be secretive and not share, you can find your help somewhere else.

If you want to be a little more open and helpful yourself, PM me and I'll unlock this.

- Chris