Engine stutters with AC on - JeepForum.com
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post #1 of 3 Old 05-04-2021, 08:47 AM Thread Starter
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Engine stutters with AC on

I have a 99 GC with the 4.7. It generally runs like a top but when I turn on the AC the whole vehicle bucks quite hard as the AC is engaged. Then the vehicle will stutter, buck, and fall on its face when I accelerate. Jeep will die at idle with AC on.

CEL also came on. Code p1391. Intermittent crank or cam signal.

Before the CEL was read I was anticipating a misfire on one coil or a weak alternator. However, now I am a little confused .

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post #2 of 3 Old 05-05-2021, 11:22 AM Thread Starter
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Any opinions?
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post #3 of 3 Old 05-05-2021, 11:35 AM
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you do NOT get a DTC P1391 until the AC is selected?

As for the AC - of course checking the belt, tight do you see it dragging ie compressor seams to stall and belt slips.

A AC check esp the HI side readings... will need a set of AC gauges.

Try this - unplug the AC compressor select AC there shpild be no difference yes no?

AC causing a low RPM - look at the IAC - cleaning esp the air bleed and pintle. There is NO P0505?

When I see the price of OEM I think aftermarket.
When I see the quality of aftermarket I think OEM.
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