1993 GMC Jimmy rough idle

1993 GMC JIMMY
177,000 MILES • 6 CYL • 2WD • AUTOMATIC
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BIGFRED1972
  • MEMBER
  • 1 POST
what could cause rough idle and excessive carbon out exhaust pipe
Dec 29, 2009 at 6:20 PM
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RASMATAZ
  • CAR REPAIR CONTRIBUTOR
  • 75,992 POSTS
Engine misfiring 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.
Dec 29, 2009 at 8:01 PM
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