I have an ls1 swapped into a C10.. it cranks but will not start.. I have constant 12v power, I'm getting power to the coil packs I'm getting rpm reading on hp tuners while cranking any suggestions for me would be great thank you again for your reading

 

Injector pulse? Check cam sensor counts with hptuners. Do u have 12v in start and while cranking?

 

I have 12v in start and crancking, I have pulse, and shows rpm when cranking.. I can't figure it out

 

Unplug your throttle position sensor. Iv seen them wired wrong and read 100% so it wouldnt start. Have you tried starting fluid to see if itll try to start on that?

 

I'm not getting spark to the plugs but I get power to the packs.. tryed unplugging tps sensor and does nothing.. and I am getting fuel this whole time but just.no fire

 

Did you ever figure out what the problem was?

 

grounds. There are usually 2 grounds rear passenger head behind intake. Sometimes one on front passenger head. And sometimes on the block either driver or passenger side near the front. I had a ls3 that had a loose ground and wouldn't fire the plugs. I had 12v at the coil harness but no spark. Tightened ground car fired right up.

 

Definitely check grounds. I swapped out the 4.8 in my girlfriends Silverado and put together a heads/cam LS1. It would turn over but wouldn't actually run. Turns out I didn't connect one of the grounds. Connected it and it fired right up, didn't skip a beat.

 

The ground at the front of the engine behind the power steering pump if not hooked up wont let it fire, so check to be sure you didn't miss it.

 

That's the one I missed. Engine would turn over, but not start.

 

Let us know when she fires. Notice I did not say "if".... lol