Q: Fast Idle does not activate when A/C Compressor engages.
Car idles normally at 750 rpm. However, when idling (such as at a traffic light), and the A/C Compressor engages, idle remains at 750 rpm (engine struggles) and does not advance to 1000 rpm, like it should.
My car has 70000 miles.
My car has an automatic transmission.
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The idle is not supposed to increase in speed when your compressor engages, rather the throttle plate should adjust at the same time the A/C engages to maintain the same RPM at idle. This will keep the idle the same with A/C on or off. If the idle drops below 750 and then jumps real high then this is a problem and should be looked at. The throttle plate, which controls the idle speed, may need to be cleaned or inspected.
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