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1994 GMC Sonoma

Electrical problem
1994 GMC Sonoma 6 cyl Two Wheel Drive Automatic 190000 miles

Will start cold but will not start after warmed up

Have replaced coil wire, plug wires, distrib cap, rotor and plugs
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Loumsc
June 19, 2010.




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.

Tiny
Internetmechanic
Jun 20, 2010.
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

Tiny
Loumsc
Jun 20, 2010.
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.
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Tiny
Internetmechanic
Jun 20, 2010.

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