84Sleeper

I got my 2002 5.3 frankinstien engine running. Took a head off and replaced a headgasket after that it started, had to use starting fluid but then ran good, I turned it off and 15 minutes later wouldn't start. I didn't have MAF hooked up though I could have flooded or fowled a plug or 8. Let is sit over night. In the morning only popped on starting fluid on maybe 2 or 3 cylinders would not start. Then wouldn't pop at all. Checked spark and absolutely no spark.

Things I've checked.
12V inginiton wire while cranking, drops to 10.6 but I believe it did that while it was running fine yesterday.

Ground to coil, good

PCM, sends data to obd2. At least coolant temp and throttle position sensor were responsive. Rpm read 0 while cranking usually read 140-160 while cranking. Not sure if that's cam or crank sensor responsible for that.

Good ground to engine body and battery.

I'm beyond confused at this point. Any tips or info would be much appreciated. It's a 2002 5.3 in a 1984 C10 with stock PCM that's been flashed. Thank you.

00pooterSS

iTrader: (40)

Check connections at cam and cranks sensor is where I would start. Also check all grounds carefully. Make sure you have a ground from the battery to the body and the engine. If you want to do a quick test for grounds grab jumper cables and connect both colors to the battery ground and connect one of the other ends to the engine and the other to the body and give it a crank.

thunderstruck507

iTrader: (18)

No spark and no RPM signal points to the problem being the crank position sensor or the wiring related to it. The sensor is behind the starter and the wires often get too close to exhaust and burn up.

I would start by looking in that area for sure.