Hello!
I have a 1989 Pontiac Trans Am GTA with the 5.7L TPI motor. It's recently developed an issue where it's idling high, too high. In park the rpm's are at 2000 and in drive its resting at 1k, but it's difficult to get it to come to stop as I have to use full my leg power on the brakes. What is the most likely culprit for a high idle issue?? It's an unmodified all original car with only 45k miles, and since purchasing it last March all that's been done to it is a tune up of sparks, wires, and the air filter. I'm on the younger side and don't have much experience dealing with older third gens/tpi motors but love these cars to death thanks to my dad. Appreciate any help and advice!
Thanks!

 

Start with checking for vacuum leaks.

 

Just for clarity, is the engine RPM reported above being measured by an actual diagnostic tachometer, or the twirly thing filling third hole in the instrument panel?