High Idle (~2000 RPM), bad AIS?

[Shelbydaytona91]

Hello, well ever since I've had my car I have had really bad idle issues. It is a 2.5 T1 auto. I am tired of it, I don't want to wear out the transmission by dropping it in drive at 2000 rpm's and its very loud and annoying. I tried to set the minimum airflow but when I adjusted the screw it was at the lowest rpm setting, turning it in only made the idle higher. The "trick" to get the AIS to shut all the way didn't have any effect on my idle either. My idle will also flucuate, usually it will start at 2100 rpms, move up to 2350 for about 20 seconds, then drop back to 2000 and remain fairly steady. In drive when I come to a stop it usually stays at a steady 1100 rpms. Ignition timing is at 12^. Vacuum reading from my stock boost/vac gauge is ~16 at idle. I completely redid my vacuum system and still had the same problem. Is my AIS bad or do my problems lie elsewhere?

[Murphy]

codes?

[Shelbydaytona91]

None

[Dusty_Duster]

Could be a bad AIS, or it could be a small vacuum leak after the throttle body.

[1FastCSX289]

The fact that the idle fluctuates indicates the AIS (IAC) is working somewhat. Check for vacuum leaks first......Then I would pull the AIS out and clean the port first. There may be some carbon or crap hanging the valve up and keeping it from closing all the way. If that doesnt fix it, I would swap the AIS. If that doesnt do it, you will have to look harder for leaks (like intake manny or TB gasket, etc) or possible wiring issues.

[mark]

there is a procedure to reset the ais...

[Shelbydaytona91]

I already tried to reset the AIS, it seemed to do nothing. I am going to take the TB off and just give it and the AIS a good cleaning and then see how things work. If not, I suppose I'll have to check the intake gasket

Do you have the pull the head off to change the gasket? I already did that once this month and I don't have the kind of money to buy a new HG, bolts, ect.

[daytonaturbo87]

The fact that the idle fluctuates indicates the AIS (IAC) is working somewhat. Check for vacuum leaks first......Then I would pull the AIS out and clean the port first. There may be some carbon or crap hanging the valve up and keeping it from closing all the way. If that doesnt fix it, I would swap the AIS. If that doesnt do it, you will have to look harder for leaks (like intake manny or TB gasket, etc) or possible wiring issues.

I agree 100% on this one. Sound advice.

there is a procedure to reset the ais...

Please explain, I've never heard of this.

Do you have the pull the head off to change the gasket?

I did it on-car on my brother's rampage. It's not a fun job, but it can be done tho I found it impossible to get the torq wrench in there to torq it properly, but it could be possible on anything that's not an L-body.

[Shelbydaytona91]

To reset the AIS, you start the car and get it up to operation temperature. Then you create a vacuum leak large enough to make the AIS close itself. After you are 100% it is closed all the way (safe to wait about a minute), you unplug the AIS and reinstall the vacuum hose. From there you use the idle adjustment screw and get it around 800-1100 RPM's (I believe thats what the manual said, could be off). Then turn the car off, and plug the AIS back in. You can also do it using a OBDII scanner I believe, that's how the FSM says to do it.

[Shelbydaytona91]

Well I have another problem, how do you get the Throttle Body off? It's just those two nuts right? I took them off but the idiots who had the car before used some goo to seal the TB to the intake manifold and unless I was missing something else to unscrew, the thing wouldn't even budge.

[1FastCSX289]

Well I have another problem, how do you get the Throttle Body off? It's just those two nuts right? I took them off but the idiots who had the car before used some goo to seal the TB to the intake manifold and unless I was missing something else to unscrew, the thing wouldn't even budge.

Two nuts/studs.....thats it. And the throttle cable and wiring. Youre gonna have to CAREFULLY pry it off.

[Shelbydaytona91]

Great, the words "carefull" and "pry" in the same sentance never end up good to me What should can I use to pry it? I tried a screw driver but it was just cutting into the intake manifold. Also what are the torque specs on the TB? My FSM doesn't even list them.

[csx711]

there is a plug on the side on the thortlebody check for voltage also check at the ecu also, chrysler spliced the wires together for the ais motor unwrap the wires and see if it got dis connected if so resoilder then will be back to normal. this happened on every TIIcar that came into the shop and my cars also..