Ecu Or Fuel Problem Car Gets Tuned Then The Entire Tune Slowly Goes Rich

[jarrod83]

Hey guys, i finally got my turbo n everything running correctly.. so i give the car a tune at first myself and after a week the whole tune turned rich again.. so i retuned it a few times then thought i may of been doing something wrong... so i called a few workshops and they just said the usual "oh it just needs a "proper" tune", so i sent it to be tuned n made 408rwhp on 19psi which wasnt to bad, so for the first few days it wasnt to bad and i runned a wideband on it... nice 14.7s on light cruise to 11.5's-11.6s on full boost..

So a few days later it started to feel abit slower and chewing a fair bit more fuel so i put the wideband back on it.. its now runnin 12s-13s around town.. n 10.9's-11.1's on full boost...

Is there anything else other than the ecu that could be causing this weird problem??

btw the ecu is a power fc pro

nismo 740cc injectors

sard fpr.. but the fuel pressure hasnt changed on it

Cheers

Jarrod

[SECURITY]

the stock o2 sensor might be messing with the afr's. what happens is you pull out the stock narrowband to fit the wideband, then tune it while the narrowband isnt reading anything. then you put the stock narrowband back in and it messes everything up again. my mate had the same problem with his pfc.

try unplugging the stocky completely and see where that gets you. your other alternative is to get your tuner to tune the car with the wideband that hooks into the rear of the exhaust and leave your stock narrowband in.

[femno]

Turn 02 Sensor feedback OFF. If your tuner forgot to do that id be really worried.

Check out Paulr33's PFC FAQ to decipher which jap symbol means OFF and which one means ON.

Keep an eye on AFRs after that.

[STATUS]

vacuum /boost leak..... cheack over cooler pipe joins etc. 02 sensor feedback wont effect anything other than cruise and light load, full throttle is derived purely from specific map values..

oh turbo could be on its way out, check boost curve.

Edited February 9, 2009 by URAS

[jarrod83]

the stock 02 sensor has been unplugged and the 02 feedback loop has been off for ages

[jarrod83]

just an update guys, one of the afm wires had got abit lose and caused all the problems, took a while to find