This probably has been discussed several times before, but the time I have to spend reading archived threads is limited. My '86 is still speed density ( although I have an A9L computer and mass air sensor to convert it) I recently took the car to the car wash. I sprayed down my engine bay and tried not to put too much pressure at the engine, only to have a high idle problem now. I have taken off my upper intake manifold and replaced all of my rubber vacuum hoses, as they were rotten and the hose going to the MAP sensor was colasped. I also took my IAC motor apart and thoroughly cleaned it. Had a spare IAC and did the same thing to it and tried these steps only to still have an idle at 1500-1800 RPM...HELP !!!!

 

I did a google search, and found many discussions on this issue after one has washed, soaked, power washed there engine.
Don't know what to tell you seeing you've checked the obvious.
Maybe the TPS?

 

Well after a couple more rotten vacuum lines below the alternator, and cleaning the tps and throttle body...so far so good, its holding a proper idle again

 

Nice

 

Good the hear!

 

Glad to hear you got it

 

I had some kind of idle problem with my 88, I removed my filter and sprayed carb cleaner in my CIA while it was running 3000 rpm to clean the mass air flow, valve, and throtle body. It did quite a good job for 4 bucks.