1999 Other GMC Models Stumbles on light acceleration

1999 GMC
190,000 MILES • V8 • 4WD • AUTOMATIC
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MCCLAUGHERTY
  • MEMBER
  • 1 POST
I have replaced the spark plugs, sp wires, dist cap and rotor, ignition coil and the V8 7.4L still stumbles under light acceleration sometimes bad enough to stall rarely but still does it sometimes.

recently the idle has been fairly errtic. Comperssion test is within in specs per manf.

any ideas I was thinking about finding out how to trioubleshoot the distributor itself.
Nov 2, 2008 at 7:04 AM
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MASTERTECHTIM
  • ✓ASE Certified Mechanic
  • 4,750 POSTS
  • ASE Certified Mechanic
i would first unplug the egr valve to make sure thats not your problem. a egr valve thats engages too quickly will make it stumble
Nov 2, 2008 at 7:17 AM
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