i have a 92' lx AT...have this really annoying problem...usually when the a/c is on or it's all muggy and hot out or i'm in reverse w/ a/c on...when i'm off the accelerator...sometimes it'll randomly rev up to like 1 or 1.5k...i forget...but it'll rev up to that and stay up there until i get on the gas again...makes it bad for braking and the torque converter...also dangerous b/c i could slam into cars in reverse...or my friends or gf could get into an accident when driving my car
it all started when we installed my aem cai...i had this problem no matter what i did...now i just have the problem sometimes...there was this hose that was taken out from the stock intake that was no longer needed...originally we capped the hose...i later learned that i was supposed to use this little piece of foam and shove it in there to restrict air flow but not block it off
really need hlp w/ this...thanks all

 

c'mon now...ther'es gotta be someone that knows

 

Maybe it was needed... The IAC valve, FITV, & a few other hoses & valves, are there to keep the idle steady when you turn stuff on (like the AC) or put it in gear. I don't have a '92, so you need to check a repair manual for your car. You probably have to reconnect that hose to a corresponding place on your new intake.

Also, look for vacuum leaks anywhere.

Or maybe your IAC valve is just dirty & it sticks open sometimes.