Intermittent engine miss

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DMC1300
  • MEMBER
  • 2 POSTS
I have a 1991 lumina eurosport, 3.1 V6 engine, 222,000 miles. After recently replacing the intake manifold gasket, o2 sensor, PCV valve, and changing spark plugs I have started experiencing an intermittent engine miss at both idle, acceleration, and freeway cruising speeds. The car will run fine then suddenly I feel a significant loss of power and hear and feel engine missing. When I come to a stop the engine will shudder and tach needle can be seen shaking wildly at about 600 rpm. When I accelerate the transmission feels like it is bucking and the engine rpms rise slowly and hesitantly until I blip the throttle and engine seems to go back to normal running for 5-10 minutes then starts missing all again. Any ideas what could be causing this?
Nov 13, 2007 at 12:48 PM
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RASMATAZ
  • ✓Experienced Mechanic
  • 75,988 POSTS
Misfires can cause the transmission not to operate properly.

Misfires can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.
Nov 15, 2007 at 8:04 AM
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