Hey all,
I reset my ECU the other day, a noticeable difference in drivability and power delivery, but no effect on the idle problem.
Went to Dr. Drift today, even he could not diagnose the problem. Had my GTR on diagnostic software, every setting was perfect from AAC response to TPS diagnosis. We experimented by lowering and increasing the AAC controller from the computer, we also switched tps off for troubleshooting purposes. But besides that all settings were nominal/optimal.
Came to a couple of conclusions:
1. Vacuum leak somewhere.
2. Throttle (inner and outer spacing gaskets) on the plenum, are somehow worn or even broken resulting in additional amount of external air being sucked in to the engine, which is not being detected by the AFM.
3. Throttle control arms are not set correctly, or have been deliberately set, to open slightly at idle rpm, but I don't think so: seem to be shutting fully.
4. ECU tuned setting: But Dr. Drift said it should be irrelevant according to software diagnostics.
I am going to check the pressure canisters at the front like 'blur' suggested.
Besides that I am going to take my car to the GTR pro's on tuesday at Hypertech Autosports, I hope GTR builder Eric Schlifelner, may help shed some experience on this problem. Because at the moment I am lost!
If anybody has any info on this, pls share. It will be much appreciated!
Cheers SAU!