Black89LX

I already know that I am going to replace my IAC on my 89,is there anything else that I could change, clean or check to help solve this problem:

The temp usually has to be at like 140 - 150 and then the idle will either sit normally at 750then rise to 1100 and back down, not really irratic or anything just for like ten seconds it will hold at 1100 then go to 750. Or it will just go right to 1500 andsit there for a few minutes then go to like 1250 until I shut it off.

Im pretty sure I just need to replace the IAC and see what happens.

But my main question is, after I replace that is there anything else that could be causing this high idle.

Thank you


Also Im not sure if this is related or not but after I start my car (whenthe engineis cold) and I put it in gear the engine rpm will kind of drop really quick like 1-200 rpm and then go back to normal, as if it were sputtering, I watched my guages when this happened and the voltmeter dropped and the check engine light came on for that second or two.....after that the car runs good.Although when I was driving tonight for like fifteen minutes Igaveit some gas and the tranny downshifted like normal I looked at my guages and the check engine light came on again and then shut off a second later. I dont know what that was about but the car ran fine throughout the drive.

I replaced the fuel pump about 3-4 weeks ago, I dont know if that has anything to do with it.

Any help is appreciated.

92hatchLX

Scan your motor and see if any codes pop up.

Black89LX

I dont think I have a scanner but thanks for your input

I was just wondering if anyone had similar problems and what might fix them

Like I said I am already replacing the IAC and was just wondering if there is anything else to fix.

Grundy

vac leaks. spray some carb cleaner or starting fluid around on all your vac lines....if it rev's up a little bit look real close at yourvac lines were you sprayed. they break all the timewhen they are that old.

Black89LX

I forgot about the vac lines.....

Thanks guys

90_Mustang_GT

If you dont want the mess use propane and go over your lines.