I'm desperate guys. I've been searching and trying and implementing and testing for 3 days and I cannot figure out why I have no spark. Working on a 2006 chevy 2500hd, 2wd with an LQ4 and 4l80e. I have crank, fuel, compression but no spark. What I've done so far
- verified <1 ohm resistance from each coil connector ground to battery negative terminal (brown wire) with key on and off
- verified battery voltage at each coil connector (pink wire) with key on
- verified pcm is sending signal for spark using data log in hp tuners when cranking
- checked and cleaned all grounds, all 4 wire harness to engine grounds, engine to battery ground, engine to firewall ground, battery to chassis ground, literally every ground I can think of and locate has been cleaned and reattached
- replaced all 8 ignition coils with known good coils from running engine
- replaced all 8 plug wires with known good wires from running engine
- replaced all 8 spark plugs with brand new ACDELCO iridium plugs
- deleted VATS
- verified good crank position signal by logging rpm while cranking in hp tuners
- checked and double checked all fluids, all full
Anybody experienced this and figured it out? Anything I have missed? I've been chasing this for 2 days now and can't figure it out. Any way to check pcm signal at coil connectors without a waveform scanner or fancy scantool?
Thanks for any input, suggestions, or help!
