AC idle issues 1982
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3rd Gear
Joined: Jul 2022
Posts: 3
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AC idle issues 1982
I'm brand new here and looking for some help on my AC in a 1982 crossfire, mostly stock. I recently had it serviced...it works, but the car stalls at idle and won't start any time the AC is switched on. Some research tells me I may need to replace or unstick an "idle stop solenoid," a mechanical plunger that bumps up the idle RPMs any time the AC compressor is on. Can anyone show or tell me where that is? I've looked in the engine bay, but I can't find the thing and don't know how hard or easy it may be to replace. I'd love to use my AC since it's working without the car stalling at every stop sign or red light. Any help would be greatly appreciated.
Melting Slicks
Joined: May 2021
Posts: 2,256
Likes: 1,299
From: Fleming Island, FL
Congratulations on your 82. Each throttle body has an electrical device called a Idle Air Controller or IAC. It's easy to identify by a 4 wire plug that plugs into them. Most likely those IAC's are bad. But it could be a bad ECM, wiring, or very unlikely a blocked IAC passage. You can either throw two new IAC'S in there or test the one's you have with a Kent Moore J37027 IAC motor driver. You can find used J37027's on eBay. Next step would be using a scanner to see if the ECM is getting a "A/C request signal". After that it's bad wiring. That would be checked with a ohmmeter and wiring diagram. Once you rule out those two things it's the ECM or a blocked IAC passage. There are no error codes for the IAC circuit. Keep in mind troubleshooting a Crossfire injection system is no different than troubleshooting any other GM TBI system. Marc
Edit: a factory service manual has a flow chart for IAC troubleshooting. A factory service manual is something you should have.
Edit: a factory service manual has a flow chart for IAC troubleshooting. A factory service manual is something you should have.
Last edited by Fly skids up!; Jul 2, 2022 at 08:40 PM.
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What he's trying to tell you is the idle stop solenoid is for carburetor cars. Yours is EFI and does not have a idle solenoid stop. Your idle is controlled by a IAC. or idle air controller. Well, in your case, 2 IAC's.
Bottom line is you need to learn a bit more about early throttle body EFI.
Simple stuff. you just need to look in the right direction.
Bottom line is you need to learn a bit more about early throttle body EFI.
Simple stuff. you just need to look in the right direction.
Thread Starter
3rd Gear
Joined: Jul 2022
Posts: 3
Likes: 0
Congratulations on your 82. Each throttle body has an electrical device called a Idle Air Controller or IAC. It's easy to identify by a 4 wire plug that plugs into them. Most likely those IAC's are bad. But it could be a bad ECM, wiring, or very unlikely a blocked IAC passage. You can either throw two new IAC'S in there or test the one's you have with a Kent Moore J37027 IAC motor driver. You can find used J37027's on eBay. Next step would be using a scanner to see if the ECM is getting a "A/C request signal". After that it's bad wiring. That would be checked with a ohmmeter and wiring diagram. Once you rule out those two things it's the ECM or a blocked IAC passage. There are no error codes for the IAC circuit. Keep in mind troubleshooting a Crossfire injection system is no different than troubleshooting any other GM TBI system. Marc
Edit: a factory service manual has a flow chart for IAC troubleshooting. A factory service manual is something you should have.
Edit: a factory service manual has a flow chart for IAC troubleshooting. A factory service manual is something you should have.
Melting Slicks
Joined: May 2021
Posts: 2,256
Likes: 1,299
From: Fleming Island, FL
You do not have to remove the throttle bodies. The IAC are very easy to replace. I would strongly recommend to you to purchase a factory service manual. It out lines testing and replacement procedures. Zip Corvette sell them. In the meantime I'm going to PM you the IAC flow chart.
Thread Starter
3rd Gear
Joined: Jul 2022
Posts: 3
Likes: 0
You do not have to remove the throttle bodies. The IAC are very easy to replace. I would strongly recommend to you to purchase a factory service manual. It out lines testing and replacement procedures. Zip Corvette sell them. In the meantime I'm going to PM you the IAC flow chart.
