I'm having idle trouble and was looking for a little direction. A little back ground first. I was drive to work on Wednesday morning and heard a noise from the engine bay and the car just died. Started it back up, and the idle surged from 2K to 3K rpm every second. When I got the car back home it seemed the exhaust manifold gasket was leaking air. Once I replaced the gasket the surging problem was fixed, but now the car idles fine with the A/C on (MAS around 50 and timing around +16). When you turn the A/C off the MAS reading jumps to 80-90, and the timing is advanced to the 30's. Any clue as to what the problem might be?

On Tuesday I changed the oil, spark plugs (gapped .022 to.024), and replace the hose from my boost controller to wastegate (it wasn't looking to good). I rechecked everything, and there are no leaks, as I also did a boost leak test on Tuesday. On thing I noticed when I finished the leak test; I noticed a little condensation on the turbo inlet, not sure if this could screw up one of the sensors, just something to think about when trying to diagnosis the problem.

Mods are:
HKS Turbo Timer
LPI 3" TBE with cat-delete
Hallman Pro Boost Controller
dynoflash -base flash to clear rev limiter etc.
ECU+
O2 housing
Fighters Garage Lower IC pipe
Fighters Garage Intake with UICP
Walbro 255 Fuel Pump
ARP Head Studs
GSC Camshafts 272i/264e
Snow Performance Alky Kit with safe injection
Spark plugs - NGK BPR8ES

All of which has been installed for at least 3 months with no problem.


If anyone can think of something let me know.
Thanks,
-Eddie

 

anyone?

 

Guys I still need help. I still have a really bad idle, as mentioned above. I've checked all the vac lines, sensors, and all IC pipes. The advanced timing is confusing. Is this an ECU problem? Is there anything else besides the ECU that can advanced timing like this. I’ve unplugged my ECU+, and the problem continuous. I’m thinking the ECU fried. Any help would be greatly appreciated.
-Eddie

 

A/F's are normal, and the check engine light isn't coming on, and today the ACD lights came on. I'm lost as to whats going on.

 

Try resetting the computer. Disconnect the battery for a few minutes reconnect, start the engine and let it idle for 10 minutes after warmed up.

 

yeah...sorry.... I already tried that a few times without luck.

 

Hi Eddie,
I am Fotis from Greece and my job is to tune some evo's here in Greece.
Your idle problem could be fixed by starting to clean your throtle body very very well and if your idle still is not stable there is a little by-pass screw on your throtle body which you can adjust the idle. If your problems insists, replace the steper motor.
I hope i could help a little bit from the far away Greece.
Let me know.

 

^^That screw is known as the base idle set screw^^....it is located on your throttle body. I dont believe that is the problem though. It doesn't hurt to check though.

 

http://images.google.com/imgres?imgu...lr%3D%26sa%3DG

Thats for DSMs....but you're looking for something similar on your Evo VIII Throttle Body.

 

yeah the screw doesn't help. Plus it doesn't explain the advanced timing. I'll check the stepper motor. The TB has been cleaned and it didn't fix the problem.
Thanks,
-Eddie

 

yeah its the stepper motor, or IACV ( idle air control valve. The meth fried it. Does anyone know where i can get one besides the dealership?
-Eddie