On start up this car idles way too high, like scary shifting it into gear. It lowers a little after driving but still needs adjustment. Sometimes the car won't shift either, usually have to turn it off and back on. Replaced the tps and vss so far. (all that did was fix the speedo). Also, unrelated but the tach doesn't work at all. Only when I turn the key on, the tach jumps down to like 4000rpms, but off or running it stays pegged. Any ideas?

 

Is it a 305tbi engine? If it is, I'd start by removing the tbi unit & cleaning it w/ carb. cleaner, get the iac removed & clean that too. The base gaskets on tbi liked to get sucked in & make a vacuum leak.

 

Ok. Sometimes the idle goes down when its warm, but not usually. Hopefully cleaning will help. Thank you!

 

This article may help also. Lots of good stuff in the technical articles section
https://www.thirdgen.org/tpimod2

 

is it a 3.1? v6

 

OOPS, I was assuming from the answer to the second post that you have a 5.0 TBI. Is that correct?

 

Yea tbi 305

 

hmm, have you secured for vaccumm leaks?