Problems with IAC

[TurboD1987]

Has any one had problems with their IAC? Mine seems to be set right then next time I start the car it is off and usually to high! Do these go bad very often and is this a sign of a bad IAC? I tried another used IAC and it wouldn't go below 59, am I doing something wrong or do I have 2 bad IACs? I'm trying to set it up for emissions and have Scotts E chip in the car. Thanks
Dave

 

[WarpSpeed]

Well, when the car's cold, it's probably going to be a little higher,, more LV8 fom thicker oil, and so on. It should come back to normal after warm up.

 

[gnXfan]

also - are you adjusting the tps in tandem? that needs to be done

plus - are you shutting the car off and restarting after each adjustment? if not and you continue to adjust - you may see 'off numbers'

_BOB

 

[TurboD1987]

Yes, I am checking the numbers when it's up to operating temperatures, and also I am adjusting the TPS with the IAC and I have been shutting it off and restarting after changing settings and it is still not working. Has anyone had a bad IAC? Any other ideas?

 

[TurboD1987]

Any body ever have a bad IAC?

 

[salvageV6]

Honestly they rarely go bad, get dirty yes but usually never die.

We used to make them here in CT.

Now they are made in Mexico.

2 bad ones I doubt it.

I would look for perhaps a vacuum leak or some unmetered air leak.

Typical failure mode is an open coil where they don't work at all.

You could try measuring accross the pins for each of the two coils.

 

[sam87]

On my old IAC, the cone-shaped valve somehow got wedged in the spring and so it wouldn't move at all. It must be able to move. When installing the new IAC, I set the distance from end of valve to body at less than 1" (manual says 1 1/8"). Until I did that, it wouldn't reset correctly.

 

[rastaz]

I had one that would read 100 at idle. I replaced it and now the one I have reads 30 at idle (which is in the normal operating parameter). Not sure what happend to the first one maybe it got stuck somehow?

 

[TurboD1987]

Ok I finally got my IAC set by adjusting slowly and turning car off and on and adjusting TPS at the same time. I got it down to 20 at idle but it didn't help my emissions test that I failed! Thanks guys for the help with IAC settings.
Dave