i have been having problems with my 93 ls. the idle jumps from 1500 to 3000 and back to 1500 then to 3000 constantly. i have serched for a vaccum leak many times. i have replaced the tps, iacv, intake manifold gasket, tb gasket, and still runs the same. i am lost for what to look for next. i went though the pcv system from that little black box on the back of the motor to the intake manifold but no leaks there. i was just wondering if anyone has had this problem or what i would be able to test next. could it be something with the computer? could the computer terminals get corroded for the water that leaks in durning the rain and cause the computer to not be getting the correct info? and ideas let me know..???

 

that little fitv valve under the TB, take the cap off the end of it, and twist the little white valve back in, they get loose soemtimes, worked for me

 

sometimes it's the little **** that makes the idle do that. Mine was surging from 1k to 2.5k, needless to say, it was frickin annoying and at part throttle it wasn't that smooth.

After spraying carb cleaner all over the TB and IM gasket area, double check FITV, etc...

It ended up being the freak throttle cable. I had it a little too tight. Cable needed a little bit more slack than I gave it.

 

thanks for the replys, i will give them a try, i know its not the cable that has more then enough slack in it but that screw i will try
thanks again