1994 GMC Sonoma Starting

1994 GMC SONOMA
190,000 MILES • 6 CYL • 2WD • AUTOMATIC
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LOUMSC
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  • 5 POSTS
Will start cold but will not start after warmed up

Have replaced coil wire, plug wires, distrib cap, rotor and plugs
Jun 19, 2010 at 7:39 PM
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INTERNETMECHANIC
  • CAR REPAIR CONTRIBUTOR
  • 700 POSTS
Are there any applicable trouble codes? When the problem occurs, have a helper crank it, while you visually check for spark at the plugs. If you have spark everywhere, use a gage and check fuel pressure. Some of the national brand autostores used to loan out a fuel pressure gage if you don't have one.

To test for spark, pull a spark plug wire loose, use a known good plug or spark tester in the boot. Ground metal part of plug/tester to metal part of engine, watch for spark, engine cranking. With temp related issues, sometimes the cts can cause problems? I don't replace anything without trying to be sure.
Jun 20, 2010 at 12:02 PM
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LOUMSC
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No there are no fault codes, Just sends back code 12 and no other codes. By cts did you mean coolant temperature sensor?

Thanx,
Lou
Jun 20, 2010 at 12:32 PM
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INTERNETMECHANIC
  • CAR REPAIR CONTRIBUTOR
  • 700 POSTS
I can not tell you the coolant temp sensor is faulty, just one possibility? I'd still want to check for spark and fuel pressure.
Jun 20, 2010 at 2:00 PM
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