ok i did the old trick flow H/I/C swap.
new vac lines, new sensors the whole deal

replaced IAC, reset tps, 14 timing everything.

when i let off onthe throttle the idle hangs around 1600 for 3 secs or so then drops down to 1100 eventhough i have set the idle at 900 (unpluging the iac)

i need to know why it wont settle down and idle at 900 or 1000.

 

Had the same prob. Heres what i did.

I cleaned my IAC.
Set my TPS voltage at .99
Cleaned my 02's, just burned them with a sterno torch.
Then i completely checked the engine over for vaccum leaks with carb. cleaner.

Then i realized it was my throttle cable binding up and keeping the throttle open slightly. I re-routed the cable a little differently and i greased up the return spring on it and the prob went away.

It was alot of trouble but my car doesnt smell like gas while its running anymore since i cleaned my 02's. And my idle is nice and smooth now that i set my TPS and cleaned my IAC.

But try messing with your throttle cable and grease your return spring on the end up the cable up. THis all started when i replaced some intake gaskets, so i pulled the intake. When i got everything back together it wouldnt run right, so i tried all of that above. Then i jiggled my throttle cable and the idle started going up and down.

 

did you reset your computer and set the base idle?

 

I bet that's it. Although I always set the idle first, and then reset the computer.

 

i have reset the idle. 900rpms.

i will have to try that throttle cable thing.

when im at a stop light the rmps wont sit at 900 where i set them to it idles at 1100

 

i was dealing with that about 2 weeks ago, ended up replacing IAC, EGR, reset tps, messed with cable, I never did remember to reset the computer, but it finally cured itself with the EGR. well for the most part now...i think i just need to reset my computer, to many electrical components replaced when its still thinking its the old stuff