I have been battling a compound issue here for 3 weeks now. NO spark or intermittant spark which was resolved by getting rid of the junk borg warner cap and rotor as well as finding a bad connection to my accell coil.
I now have uninterrupted spark. My tach always registered the spark signal though.
I am now running into a very choppy idle and severely lean issue. I know on the TBI models like my old one , it used the spark reference signal from the module to know when to fire the injectors. I replaced that. Didn't run at all. Put a good known one in and back to full spark but still crap idle.
I have no converter on my truck so I can usually smell a little fuel smell in the exhaust. It's so lean that it smells like the truck is going to catch on fire. The heat from the exhaust is insane. I have tried swapping my old injector back (thought it was bad but it was the dam plastic fuel lines , replaced it about 4 years ago). Still same issue. I bought a fuel pressure gauge and it seems to hold fuel pressure just fine. I know the vortecs run over 55psi.
Do you think this could be a bad PCM? I am at the end of my ability to diagnose this thing.

 

could be the MAP sensor

 

makes no difference wether the MAP is plugged in or not. Haven't tried swapping it out though , but unplugging it should make it do something different.