Stalling issues?!?

[Pitbull Kustoms]

My 89 has been giving me fits with a curious stalling problem. I've replaced the idle box?? on the intake, reset the idle and it only works for a few minutes then it starts again.

Let me start by telling what happens. If you go over 2000 rpm and take it out of gear, to slow down, it drops to 1000- then 500 and 50/50 whether it stalls out or not. If it decides to stall the CEL comes on, no matter what you do, taking your foot off the gas means a stall. It then fires right back up and the CEL is out.

Any ideas on what it is? I've also noticed when it starts trying to stall, the power goes up and down as well. It doesnt chug or miss fire, just wants to die?

Thanks!

 

[hawkeye18]

Pull your codes. It sounds like an IAC but if you replaced it (and assuming the replacement part was good), then that's not it. It also might be a VSS. a bad vehicle speed sensor will also cause problems when letting off the gas to idle if you're at speed. Other than that... again. pull your codes, let us know what they say, we should be able to help you from there. Good luck...

 

[Pitbull Kustoms]

My mechanic buddy just told me the exact same thing. The VSS. Now I just need to pull it off my parts car and see what happens!
Thanks!

 

[Pitbull Kustoms]

Strange thing happened. I went to start it up and 0, no power to anything. I unhooked the battery, then put it back on, fired right up. The problem seemed to go away. Today it started again!
I got the new VSS and will install soon.