99 GMC 2500

  • Tiny
  • Marshallkendrick1
  • 1999 GMC C2500
  • V8
  • 4WD
  • 245,000 MILES

99 gmc 5.7 vortec hard to start when it is warm doesnt do it always run for awile the shut down 15-30 min try to start backfires hard to turn over misses when it does start it runs ruff till you take it out on hiway it will do this if you start it and let it idle a long time once in a while it wont start untill you let it cool down a long time new fuel pump cataletic converters 02 sensor no codes runs good starts good cold

Do you
have the same problem?
Friday, January 7th, 2011 AT 3:52 AM

1 Reply

  • Tiny
  • Rasmataz

Clean out the idle air control valve and EGR valve and test throttle position and manifold absolute pressure sensors-

Was this
Friday, January 7th, 2011 AT 4:40 AM

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