Quote:
Originally Posted by kyral
doesn't a vacuum leak usually lead to a crappy idle?
I would think thered need to be an extra fuel problem in conjunction with the vacuum leak to create a high idle.
have you tried adjusting the iacv? not just rplacing it.
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Disconnect the vacuum line at your brake booster while your engine is at idle and see how it responds. It's a good theory-to-practice test as you can connect it right back up once you've confirmed what we're saying. This creates a large vacuum leak so you'll see engine speed raise quite a lot.
FYI the ECM uses a 2D table utilizing load% and RPM as axis. It measures your load by airflow through the MAF (density compensated by temperature) and RPM off of the CAS. You will cause RPM to go up and load to stay the same(because the air leak you're creating bypasses the MAF) but, yes, it will add more fuel based on the new VE table conditions it is now seeing. It would be lean-ish but that's beside the point; the motor will rev up.
A quick dummy-check on whether you've got a vacuum leak or not is to pinch off the line feeding your IACV/AACV (the 5/8" line going from the intake to below where the upper radiator hose connects.) Under normal conditions (without a vacuum leak) the engine will stall out and die. If there IS a vacuum leak from something other than the IACV/AACV, then the engine speed will lower but it'll still be able to idle.
Back to the main topic, assuming OP has solved the problem as this is over 2 months old with no follow-up from them.