Hi guys! My PA Ultra has been having an akward high idle issue that has got me and oldsman105 stumped. When in idle the car idles at 2500 rpms. The car was in tough shape when I got it. The prior owner seems to have tried to fix any kind of problem the car had with glue. I have so far cleaned the throttle body, changed the TPS sensor, idle air controller, and have checked for vaccuum leaks, and finally today Oldsman and I changed the super charger coupler. when we changed the coupler we noticed that the original supercharger coupler was cooked off and only a small piece was left, so we figured that was the big vaccuum leak. When we started the car after changing the coupler the supercharger ran fine but the Idle started around 1,300 rpms, but quickly build up to 2500 RPMs. When we gave it a little gas the rpms dropped, but when it idled again the car once again rose to 2500 rpms. Oldsman and I are stumped and have no more ideas as to what could be causing the problem. Any help or advice would be greatly appreciated!

Me thinks it'* gotta be a vacuum leak. But what happens if you pull the vac line off the fuel pressure regulator when it'* idling?

Oldsman has tried that with various vaccuume lines (fuel pressure regulator included) and what always happens is that the idle goes even higher so I shut down the motor before something breaks.

Is the throttle plate closed completely at idle? Perhaps the throttle linkage needs adjusted.

You mean the throttle body gasket linkage to the engine?

I mean the cables that attach to the throttle body. One comes from the pedal, the other goes down to the cruise control and can be adjusted down on the cruise module.

Yeah sorry I forgot to metion that we did scan the carputer. We did not get any kind of codes. The only thing that I though was out of place was that. The computer said that the TPS was open at 6% throttle.

Ah, so your TPS is adjusted wrong or the throttle is indeed a little open.

Yeah we did make sure that those were linked properly.