I need help. I'm trying to find out if anyone has been there done that. Or has any possible solutions.
I just got done with a engine swap on a 02 Fbody. I sealed it out with a gen 4 5.3l.
I did some Upgrades on the motor like heads and cam. All new sensors around the car. Like crank/cam etc. After getting it started today I let it run up to operating temperature and it sounded good like there wasn't really any issues other than me popping the gas a little and it stumbling a little to figure out its idle. In running off of the stock PCM tune. Afterwards I turned the motor off and went to start it back up shortly afterwards. And nothing it just cranks and cranks. And seems like it could possibly backfiring. Or the timing is off. I'm thinking maybe it could be the new crank and cam position sensor. With a untuned PCM.
also my tachometer wasn't working either. Any suggestions?
keep in mind on that first run I didn't have any O2 sensors plugged in. Does anyone have any possible solutions? If you have any questions about the situation please ask!! Need help ASAP!

 

I would put this in the tuning section. I am pretty sure if you have no tach that it has something to do with the crank sensor.

 

If it is gen 4 that means you did the cam position sensor relocation harness. They are almost always wired backwards, you need to swap the 2 outside wires on the cam position sensor harness.