rough idle when cool a/c on
this started a while back and is getting worse.
If the shut the is car off on a warm day, the a/c selector is left in the max postion full cold (turn to the left). Most times on start up the car runs rough like a cyclinder missing, or a bad plug/wire. until the temp guage climbs up into the normal range, when stopped at a light with car in drive and foot on the brake the whole car buzzes and vibrates.
Well i took the car out yesterday (usually my son drives the cat) and this phenoma happened, he said "see day thats what i'm talking about". I reached over and shut the air off. the car settled down smooth as silk, the idles was rock steady at 550 rpm , the perfromance from a standstill was impressive. After a few minutes i turned the air back on no problem. latter in the day i repeated the sequence, had the same problem when cool, till i turned the a/c off. 5 minutes later turned the a/c back on and no problem.
So what in the start up/cold engine scenario is so adversvley affected by the a/c compressor? Is there a sensor malfuntion? A/c works fine, the pressures are in range both sides. new plugs and wires within the past year.
any thoughts ?
i'd rather go slow than not go at all
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