1996 No start no spark

[TexasRebel]

1996 C1500 4.3

Truck died in the middle of an intersection and decided to no longer have spark. Changed coil, ignition control module, cam sensor, and crank sensor. Still no spark. Can't seem to track down what failed. Any ideas?

 

[smdk2500]

Fuses good in the under hood fuse box

 

[Schurkey]

Do the ignition module and ignition coil have power? Should be system voltage--9+ volts when cranking, 11+ volts with ignition on, engine not running, and 13+ volts when the engine is running and the alternator is charging.

Pop the cap off, verify that the rotor turns when you crank the engine. Vortec distributors are known for wearing-out the distributor gear. Vortec distributors are also known for failed distributor caps, and to a lesser extent, failed distributor rotors. Excessively-worn bushings in the plastic distributor body are another common problem.

I hope you saved the old parts--coil, module, sensors. The original stuff is likely better than the "brand-new" parts just installed.

 

[HotWheelsBurban]

If distributor is working (turning like it should) rotor may be bad. I had that happen on my Burb, replaced the crankshaft position sensor and it didn't fix it. Rotor did.

 

[TexasRebel]

Fuses good in the under hood fuse box

Yes. That was the first thing I checked after confirming no spark.

 

[TexasRebel]

Do the ignition module and ignition coil have power? Should be system voltage--9+ volts when cranking, 11+ volts with ignition on, engine not running, and 13+ volts when the engine is running and the alternator is charging.

Pop the cap off, verify that the rotor turns when you crank the engine. Vortec distributors are known for wearing-out the distributor gear. Vortec distributors are also known for failed distributor caps, and to a lesser extent, failed distributor rotors. Excessively-worn bushings in the plastic distributor body are another common problem.

I hope you saved the old parts--coil, module, sensors. The original stuff is likely better than the "brand-new" parts just installed.

Power going in to both, nothing come out of coil. Dist is still turning as should. Cap and rotor are pretty new with only a couple thousand miles on them. No corrosion or obvious signs of wear.

 

[TexasRebel]

If distributor is working (turning like it should) rotor may be bad. I had that happen on my Burb, replaced the crankshaft position sensor and it didn't fix it. Rotor did.

Rotor was just replaced a couple thousand miles ago. No obvious signs of wear or failure.

 

[TexasRebel]

I've replaced every sensor involved and checked all wiring. New pcm has just been ordered.

 

[Schurkey]

Did you ever connect a scan tool, to see if the ECM was getting a "crankshaft turning" signal?

HOW did you "check" all the wiring?

 

[TexasRebel]

Did you ever connect a scan tool, to see if the ECM was getting a "crankshaft turning" signal?

HOW did you "check" all the wiring?

I can't use a scan tool as when someone attempted to steal the truck a while back, they hacked up the wiring going to the port and I keep forgetting to go buy a replacement port. When checking the wiring for all of the sensors and what not, I pulled back loom and tape to make sure nothing had any burnt or broken connections and checking to see if there was any input/output signals.