1994 gmc 1500 backfiring

1994 GMC C1500
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JACKCAN73
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  • 1 POST
I recently changed exhaust manifold, spark plugs and plugwires. Now my truck backfires when reved up, and driving very slugish and studders alot? 1994 gmc sierra 4x4 automatic 119,000 mi v8 5.0l
Nov 12, 2007 at 4:37 PM
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RASMATAZ
  • ✓ASE Certified Mechanic
  • 75,992 POSTS
  • ASE Certified Mechanic
Check the routing of the spark plugwires could be crossing over to an other wire. Sparkplugs with wrong heat range,ignition timing off, too rich or lean fuel mixture,hot valves and carbons in the chamber.
Nov 13, 2007 at 2:50 PM
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