20 Most Recent 1999 GMC Sierra 3500 Questions & Answers

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check fuel pressure should be 42 lbs. check filter if low some engines have 2 filters

You can have someone stand by the truck and they should hear the pump kick on when you turn the key in the on position. Can you spray fuel into the throttle body and will it start that will tell you if the ignition is ok or not and also tell you if you have fire to the cylinders. If it start right up and shuts off you either have a bad fuel filter, fuel pump or a plugged catalytic converter in the exhaust system.

Stalling when the engine is running could be faulty spark.look for faulty cables also.
Change the plugs and cables if you have nt done that during last maintenance

The ignition module is under the distributor cap. Mark the spark plug wires location then remove the cap. Remove the 2 screws and connectors.

Replace with new bulb you must not touch the glass part of the bulb.oils from fingers will cause it to burn out, also make sure that there is no condensation inside of the bulb housing as this will cause the bulb to short out and possibly cause a fire

There are two ECM fuses - marked ecm 1 and ecm B.ECM B powers the fuel pump and the Veh control module which handles most of the sensors.ECM 1 powers the ignition module, coil, injectors and the rest of the engine sensors.You may need a repair book with diagrams to check all of the circuits for shorts.

you have a wire grounding out somewhere. The only way I know how to find it quickly is not very safe and requires extra work later.

spark plug wires or coil pack

Yes, the system is called Passlock, and malfunctions regularly. Go to this link for an explanation of how it works, plus some tricks and tips on how to reset it, or bypass it.http://vatspasslockpasskeysecurityhelp.yolasite.com/

For the ECM 1 fuse to open you obviously have a short to ground , start with the injector disconnected and see if ECM 1 fuse still blows.If it does disconnect crank sensor, also inspect wires for the injectors or any rub through wires here is a diagram