Idle when A/C is on?

[Brittany]

I have a 93 GS-T.

Obviously, like everyone else, I have idle issues

When the car is running with the A/C OFF, it idles just fine.

When I turn the A/C on, the idle lowers approx. 300-400 RPM and I lose all power and the car dies when I let the rpm's drop to idle speed at a stop sign.

I have adjusted the idle up and the A/C will run and the car will idle but I get idle surge when I turn off the A/C.

So, what's the deal? Also, the dash and steering wheel shake pretty bad when I turn on the A/c, like a rumble.

I just want to fix whatever this is.

Thanks,
Brittany

 

[David15151]

Sounds to me like your AC compressor is wanting to lock up. It may be on its way out the door. The engine is having a hard time turning that compressor wheel when its on. That would explain the problem with idle and so forth. It's real fun when the thing seizes on you and you are driving down the road... basicaly the engine wants to die cause its on such load.. yeah ive done that before.

 

[Brittany]

Would that also explain the vibration?

How much is a new compressor?

If not that, how about the idle control? Why does the idle drop so much? I thought the solenoid was supposed to correct the lower idle.

Brittany

 

[CurtTSI]

Check your ISC servo. This is what you see when the ISC goes bad. If you also have idle surge, the ISC is probably the problem.

 

[Aurora-Hybrid]

hey there Brittany, it sounds to me like your Idle Air Control has died. you can order another one from Auto Zone or somewhere like that bt they are pricey. I replaced mine when I first got my car. But once you do that it should idle just fine.

 

[Brittany]

Ok, do you happen to know the exact name or part number?

I hope this solves the problem. How hard to install and where is it located? How do I test it to verify it's bad?

Thanks,
Brittany

 

[CurtTSI]

The ISC is located on the lower left side of the throttle body. It should have a light brown cover and attaches to a 6-pin connector. Pull off the connector and measure the resistance between the 2 center pins and the pins on each side of it, a total of 4 measurements. Use a digital volt meter. Resistance should between 28 and 33 ohms cold. Resistances might be a bit higher if the ISC is warm. If one of these resistances is very large (open circuit), one of the coils in the ISC is bad. The ISC attaches to the throttle body with 2 small bolts, but you should be able to make the measurement without removing it.

 

[Brittany]

Thank you. I will be sure to do that before blowing $300 on another one.

 

[Aurora-Hybrid]

Good lcuk!!