1991 GMC C1500 Holley TBI

1991 GMC C1500
234,000 MILES • V8 • 2WD • AUTOMATIC
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PAT DONOVAN
  • MEMBER
  • 1 POST
I just intalled a holley 670 cfm TBI on my truck now the engine idles and runs ruff until it warms up,the engine has been rebuilt,I've installed dual exhaust,hypertech stage 2 chip,K&N cold air intake and headers but it doesn't run as well as I had expected,is their something I've missed and do you have any suggestions.
thank you
Jan 2, 2008 at 9:50 PM
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MHPAUTOS
  • ✓ASE Certified Mechanic
  • 31,937 POSTS
  • ASE Certified Mechanic
Hi there,

The first thing to do is run the engine cold with an exhaust analyzer, it may be a case of to rich or to lean, check all vacuum ports and hoses, nothing left off or on the wrong port. If you have just bolted it on out of the box, it may have incorrect float setting, anything could be out. so to see what the emissions are up to will be a good place to start,

Mark (mhpautos)
Jan 3, 2008 at 1:59 AM
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