When I'm idling, the car sometimes revs between 500-1000 rpm, over and over again until i start moving. It generally only happens when the A/C is on....
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2002 Chevrolet Cavalier Question: engine revs up and down when idling, only when A/C is on
Answer #1shadetreeauto October 05, 2010, 08:08Journeyman
this may be normal as the idle will kick up when the ac compressor cycles on and off.
Answer #2Visitor, November 18, 2010, 13:32
You could have a vacuum leak or the fans are not working. The fuse box in the engine compartment left fender there is a relay for the A/C and one for the heater fan. The one for the A/C controls the fans. Switch the A/C and blower motor relays, turn on A/C, If the fans come on the relay will cost about $10 .