Big Turbo Help

[gotaudi]

Hello I have a 2001 Audi A4 1.8T with the following mods:

GTRS Elim. Unitronics software, ATP high flow mani, Neuspeed TIP, Custom intake, Labree HFC, Apexi AVC-R, APR Exhaust, Precision FMIC, Bosch Green giants (440cc) running at 4 bar, Vr6 MAF housing with new stock sensor.

I am having the following problems:

I am pulling close to max timing during moderate to heavy throttle.

my fuel trims are:
1.5% at idle
24.2% part load
I dont have any vac/boost leaks that I can find. the timing pull is the same at 14psi and 20psi. Race gas does not help with the timing pull.

I think it might be the ecu. does anyone have a 2001.5 (CH box) big turbo A4 that will let me swap ecu's long enough for me to log.

please let me know

Thank you

[CMH]

Are those fuel trim readings + or -?

[gotaudi]

Those fuel trims are positive (+) but when I log the a/f ratio (2001 A4 use a wideband o2 sensor) it is spot on with requested A/F ratio.


I dont know where I can take it to for them to diagnose my problems.

[CMH]

Sounds like the maf might be going bad causing lower then normal readings which makes the ecu add more fuel which is why both the idle and part throttle(some boost) fuel trim readings are saying the ecu is adding fuel for both. Only other thing it could be is that there is a leak between your turbo and maf allowing unmetered air into the system.

[gotaudi]

I have changed the MAF sensor twice now and get the same problems. a boost leak would cause a rich condition (more fuel less air) and a vacuum leak would cause a lean condition (more air less fuel). I don't know what is causing these problems.