Idle problems, I have checked everything I know of.

[khartley]

I've had a bad idle for a long time now, and I've tried everything I can think of to get rid of it, and it won't go away.

I replaced the O ring on the BISS screw.

Tested for and fixed all boost leaks.

Tested TPS, has 4.95v

Replaced tb shaft seals, cleaned tb.


What it does is vary from 500 rpm up to 1500, sometimes it will even itself out for a while. When the idle is jumping around, so is the wideband, going from 13.5 all the way to 16. When the wideband goes lean, the idle goes down. Even while I'm driving I can feel it a little, and the wideband still won't stay still. Ever.

Today, I unplugged the TPS, the idle did not change at all. I also unplugged my GM 3" Maf, and the idle did not change (weird???) Then when I plugged the maf back in, the car died. I am attempting to tune with a Maft Pro.

Any thoughts, ideas? I have run out of things to check for.

 

[khartley]

I have rebuilt my throttle body with all new gaskets, so that shouldn't be the case.

I have a leaky turbo, but my maf is by the throttle body and I have no leaks from the maf on, I don't believe anything before would cause idle problems, but then again.. I have been wrong many times before.

I have tested and tried replacing the isc, no luck.