maybe try changing the plug wires?...sometimes its hard to see them arcing

 

You could try running a continuity check on the coil wiring harness back to the PCM connectors. Maybe some thing got pinched or burned.

check your plugs are torqued correctly and not cracked.

try changing your o2 sensor in that bank?

 

Is it possibly a timing issue? Could it just suddenly lose or skip timing, but not run enough to be popping and back firing?

I'll give it a try on lunch and see what happens. I have swapped plug wires from cylinder to cylinder with no change.

My o2 sensors are fairly new. I replaced the old bosch ones I had with some new factory a/c delco ones. As far as the wiring goes, could I have a wiring issue but still have spark? I have confirmed the dead cylinders are sparking.


I really appreciate all the help from everyone. I don't post much, but I have been lurking on this site for a long time. Lots of knowledge and great advice to be had here.

 

Well, still no luck. I tried some new plug wires to no avail. I took the intake manifold and valley cover off to see if I could inspect the cam for worn lobes. The cam looked in great shape. Its as if its mechanically in time but electronically out of time. I'm going to pull the starter today and see if i can inspect the reluctor wheel on the crank. Maybe it slipped? If I don't see anything there I may just throw a new crank sensor in it and see what happens.

 

Try a crank angle sensor error CASE relearn as well.

 

Well, I gave it a try today, but I couldn't get past the first step. It would never hit the 4000rpm fuel cut off the tech 2 listed. It would just rev to the limiter. Any other guesses?

 

I would check your injector fuses and wiring. Make sure all injectors get power and have a good ground. If that's not it get the injectors tested somewhere or swap out or different ones?