High Idle Issue...

DIGItonium

Some of you guys my have been aware about this issue I've been having. The idle surging idle is mostly fixed after replacing the poor quality "leaky" oil catch cans with ones that are properly sealed (Morimoto) along with proper fuel line hoses for the PCV. I also tightened the PCVs on the valve cover, trimmed and tightened hoses. There's no oil vapor residue anywhere.

Upon warming up idle is so much lower and virtually stable, so it wasn't surging like it did before. However, after driving for awhile (as things heat up), it starts surging slightly (nowhere near as bad as before). Then after 15 minutes of driving and stopping at the light, idle starts hanging around 1-1.2k. If I tap the throttle, the engine revs to 3-4k RPM then slowly back down and back up to 1-1.2k. Up until yesterday it would hang long enough to throw a high idle code. When it does idle high, in 1st the car would accelerate as if the throttle is stuck and I had to hit the brakes to slow it down. At this point the cooling fans are running, and there's lots of heat. No overheating issues.

The work around is to shut off and restart, and goes back to idling low and fairly stable. Some suggested it might be a tuning issue after doing all the maintenance work last year (spark plugs, clean throttles, etc.).

Other than that, engine is smooth, boost is stable, and there's plenty of power.

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