I have a 1992 ford escort lx that I just got and it is a great car cheap on gas a great work car but the only thing is the av doesn’t work. I can turn on the air to cool but when I turn on the ac my car stalls out. So my question is does anyone know what the problem is?
The first thing I’d check is the Idle Air Control system. That’s supposed to keep the idle at the necessary level to keep the engine running regardless of the load on it.
If you can feed it a bit gas in neutral and then it doesn’t stall out when the AC is turned on, then the problem is not idle control. I’d suspect the compressor is jammed, so when the compressor clutch tries to make the compressor rotate, it can’t and the huge load on the engine causes it to stall.
As stated, the problem might be with the Idle Air Control valve.
To determine if it is, with the engine idling, slightly step on the accelerator to bring the RPM"s up and then turn the AC on. If the engine doesn’t stall out when doing this, the problem is with the IAC valve.
IAC and spark plugs. When was the last time plugs were replace?
I agree with Testers logic, but for that year, the issue could also be the TPS. Back in that era, the TPS had two parts, the throttle position sensor and the idle position switch. If the idle position switch isn’t making with your foot off the gas, then the IAC will not get control signals from the computer.
Another thing to check for, that I’ve found fords are very particular about is to make sure the throttle body/plate are clean. You’ll also want to make sure that it runs on its base idle. Start it with IAC connected, then disconnect IAC electrical connector. The engine should continue to idle on its own, probably somewhere around 600-700 RPMs. If it can’t run on its base idle, then ECM/PCM can’t properly control the idle when there’s an added load. Could be a locked up compressor as others have stated.