96 monte 3.4 iac question

[1320-camaro-383]

My 96 monte is idleing at 2-3k rpms.The iac reads 74 with the car off and 98-105 running.Does anyone know what it should run at?Thanks

[blazes9395]

Is it setting any codes? Do you have any idle problems, is it fluctuating up and down? Did you check for vacuum leaks?

[1320-camaro-383]

Hey thanks for trying to help,I was about to give up on this forum.Anyways no codes are being thrown.When I start it it idels from 15oo rps to 3500 rps.And if it idels at 1500 it will quickly raise to 300-3500 rpms.When I put it in gear it will go down to about 1500-1700 but thats still way too high.I just bought it and it was like this.I thought it was the tps because when I hooked up my mac/otc scanner it showed no activity on the tps.So I bought a new one now it shows thats working but that wasnt the idel problem.So now Im thinking its the aic valve but it was replaced not that long ago and I took one out of a newer 3.4 the bolts didnt line up but it fit so I held it in,started it and no change.Im thinking it could be the ecm sending it to many pulses seeing asthough it doesnt recognize a problem.So what do you think?

[blazes9395]

After it warms up, does the idle come down to normal levels? If this is the case, then its almost for sure the lower intake gaskets. If the idle stays this way no matter if it warms up or not, then you most likely have another problem. Also make sure you don't have any vacuum leaks.

Another thing, check and make sure you throttle plate is closing all the way. If its dirty with carbon, etc, then this could give you an idle problem.

[1320-camaro-383]

All good points.The throttle plate isnt sticking at all,it is completly closing.As for your idea on the intake gasket,I haveent wanted to run it very long ideling that high so Im not sure it has warmed up completly.I will let it and try that.Are you talking about the manifold to head gasket?I have never heard of this causing high idel.I did check for vacume leaks and didnt find any.Thats not to say there isnt any.Wouldnt a vacume leak lower the idel?Thanks for your input.