Help me with spark?
 

I have a 1968 Suburban. I've got the LM7 installed and have been chasing spark problems for a minute. I've posted on Reddit and over at LS1tech, but thought you all might have an idea. Here's what I posted over there:

I'm trying to get an 04 LM7 to run. I had it idling, but had no throttle. That turned out to be I had a 6 pin cable to the TAC instead of the 9. Before I figured that out, I was checking the wiring to the Throttle Body for breaks. Now I have that pedal cable swapped, and I can hear it moving the throttle body, but I don't have spark.

Before I make a bigger mess out of this, can someone please confirm what kind of power I should be seeing at the connectors for the banks of coils? I currently (pun firmly intended) see 12V from the pink to every other wire in the connector with the key in the run position. No other combination shows volts. Is that right or have I shorted something in that harness to ground? (my understanding is that spark is commanded by the PCM grounding but I don't know what it should look like in the run position)

Re: Help me with spark?
 

OK, I've spent some time experimenting with a multimeter. I have continuity to ground at the ground pin on the coil jumper harness and on E, which is a brown wire which I THINK is the low voltage reference which should go to ground. No continuity to ground anywhere else, so it isn't a broken wire, voltage/ground to complete circuit is coming from the PCM.

Does that mean the PCM is bad or does that mean the PCM is ok and something else is wrong? I have RPM signal logging I crank, so that tells me the CPS is ok. Right?

Re: Help me with spark?
 

with the key in the on position, there should be 12V at each coil. In my harness they are all wired together and off the same relay circuit.
I would pinpoint test for voltage at EACH coil. I chased a miss for a long time until I discovered a bad connector for the coils.
I also purchased an HPtuners scan tool to help locate some other issues. That helped me a lot.
The PCM should do the grounding to fire each coil, so I don't think you should see continuity to ground when testing with DVM.
My swap has DBC so I can't offer any input on the pedal. I do know that the pedal and TAC have to match the operating system of the PCM or it won't accelerate.
Sorry I can't be of more assistance. Good luck figuring it out.