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Posted on Mar 12, 2009

Check engine light comes on temporarily - engine chuggs at idle

Check engine light comes on for a day or two at a time, jeep runs rough at idle but runs smooth under acceleration and at driving speeds. No loss of fuel mileage. Have run scanner but doesn't record any engine codes when check engine light is on or off. Only shows #1 cylinder miss on every stroke. Have checked compression and consistent on all cylinders. Checked fire on plug wire and checked load on new wires everything good. New plugs and has never fouled plugs. Has new distributor, rotor, cap. Have checked fuel pressure and in normal range. Fuel rail clean, tested injectors no problems decided to change injector on #1 cylinder to be safe. No change. Have checked all vacuum lines everything okay. Have used node light to test injector pulse everything okay.

When check engine light is off the engine runs smooth at idle and operates normally. When check engine light comes on the engines runs extremely ruff and sometimes chuggs like it wants to die. When you accelerate it runs smooth and strong and runs smooth but chuggs when the engine comes to idle in drive or in neutral. I have tried everything am wondering if it could possibly be a bad pcm.

  • mamaconnie May 23, 2009

    2000 Jeep Cherokee, check engine light comes on, runs rough. I've had it looked at by jeep mechanic, who can't figure it out. they tried wrapping the #3 injector, helped for a few miles, then cel back on. Have you found a solution?

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  • Posted on Mar 12, 2009
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Before changing you pcm try cleaning your egr valve. remove the valve and see if its stuck in the open position if so use a small pick to clean around the spring.

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