1999 GMC Envoy won't start

[bjhatfi]

All electric works lights, radio, power windows, etc, it will turn over but won't start. The battery is good and, The check engine light isn't on either.

[carriedi]

the check engine light comes on when you turn the key on but the engine hasn't started yet. Should go off while cranking. Until the engine starts up, how do you know you don't have the check engine light on?

Any time you have a crank no start you need to check for spark, fuel pressure and injector pulse. Depending on which one or combination of ones that are missing will make a difference on which way to look

[bjhatfi]

bjhatfi wrote:
> All electric works lights, radio, power windows, etc, it will turn over but
> won't start. The battery is good and, The check engine light isn't on
> either.
I guess what I was trying to say prior. That the check engine light never came on prior to the envoy not starting. Also when I turn the ignition all lights come on, but fuel level reads empty when it is not. It turns over, but doesn't start.

[carriedi]

ok, do you have spark? do you have good fuel pressure? (different engines use different fuel pressure specs) and have you checked for fuel injector pulse?

Do you hear the fuel pump come on when you turn the key to run? (not the start position just when the lights come on on the dash) You should have a 2 second prime when the key goes into the run position. There should be a relay that clicks on, the fuel pump turns on and runs and then the relay clicks off and the fuel pump turns off. Most of the time you can hear it. If you can't have someone else cycle the key while you go back by the tank and then see if you hear the pump run.

[Guest]

I have a 2004 envoy v8 I have been having similar issues.

[carriedi]

when you have a "crank, no start" condition you have to check for the basics first. Fuel pressure, injector pulse and spark. No crank sensor or cam signal means the computer doesn't see the engine turning over so no spark and no fuel injector pulse. bad ignition switch could mean engine cranks over, no power to fuel pump or computer. Bad fuel pump could mean no fuel pressure so no start. bad ignition passlock sensor could mean the engine starts but then shuts down because not recognizing the key (security light flashes). Bad coil, bad distributor rotor, distributor pick up could all affect spark.

Distributor cap on this model is common to cause misfires and a no start condition because the spark burns through the cap and jumps to other spark plug terminal contacts.

be very careful if you replace the distributor cap. the distributor cap mounts with two screws that go into a plastic mounting plate. They strip and crack very easily. So, just tighten until the cap touches and then only finger tight.

fuel leaks inside the plenum could cause the engine to flood with gas.

Plugged exhaust.


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