I have the 1996 silverado 350. I have a Haynes repair manual and have done a few test. The problem was bucking but sometimes the truck would run just fine. I had the ignition module checked at autozone. it tested bad they said and i got a new one. However, the code came back the next day.
I did all the checks on the coil with a volt meter. It checked good. The ignition module, coil and crank position sensor all have 11.5-12 volts supply voltage. The ground wire in the harness has continuity to battery ground.
Checking the ignition control module harness white wire with a voltmeter on AC mode should yield "approximately"1.0 to 4.0 volts with the engine cranking. It yielded 6.0 volts in my test. it says to check the crankshaft sensor if the voltage is out of range. Backprobing this sensor with a voltmeter on AC should result in "approximately" 5.0 volts. My test resulted in 3.9-4.0. The manual then says: "If a CKP sensor signal is not present, replace the crankshaft position sensor."
Well, my voltage was out of the 'approximate" range, but a signal was present.
It goes on to say if the ignition control module test and the crankshaft position sensor tests are ok, to have the PCM checked at a dealer.
This is my daily driver but the truck has 342,000 miles so I dont want to spend to much at a dealer.
Where should I go from here? Replace the crankshaft position sensor? I have read something about there being a "relearn" process that has to be done by a dealer sometimes when replace ing this sensor? Could I still drive it?
I really appreciate your help!