1988 gmc k1500 5.7 tbi 5 speed runs fine when cold but misses when warm any suggestions?i

1988 GMC TRUCK
18,000 MILES
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D61562
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  • 1 POST
i've changed fuel filter,egr valve,dist.cap and rotot button,and pickup in dist.
Dec 10, 2011 at 4:42 PM
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JDL
  • ASE Certified Mechanic
  • 16,098 POSTS
  • ASE Certified Mechanic
You might do a cylinder balance test, when the problem is ongoing. You usually kill the cylinders one at a time, quickly, by killing spark, Pay attention to the rpms, if you kill a cylinder that has no effect on the rpms, that cylinder is either dead or very weak, then you check fuel--spark and compression on that cylinder.

Any applicable trouble codes? You can check mil codes, yourself. Use a gage and check fuel pressure, when problem is ongoing. You could have a vacuum leak that only shows up after it is warm.
Dec 10, 2011 at 5:55 PM
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