Originally Posted by wretched73

2005 Silverado, 5.3 to 6.0 swap

6.0, bored .030 over, K1 crank and rods, 212/218 112 LSA .550 lift cam, NNBS intake and injectors, LS3 gold blade TB w/ Newest gen X Link, tuned by local tuner, 5.3 had a black bear EFI live tune, new tuner rewrote with HP tuners.

Has spark and fuel.

Engine cranks but will not start, popping (backfiring) through intake and exhaust.

Crank and cam sensor were brand new, then swapped for the originals from the running 5.3. All plugs/grounds checked, still same issue.

Sounds like it is 180* out, crank does have 24x reluctor wheel with correct black crank sensor, due to the length of the wiring harness, not possible to swap coil pack harness or injectors.

Security light goes off, does not stay on, so I do not think it is a VATS issue. Blackbear sent a new computer with a tune when they tuned the 5.3, I had to do a security relearn at that time.

Any ideas? At a loss here. Thinking it has to be tune related but the tuner is a respected local tuner and I wouldn't know how to diagnose if it was tune related anyway.

Originally Posted by Stepside Silveraydo

Hey wretched73, I know this is an old thread but you are having the same issues that I am currently and your the only one that says it sounds like 180° out like mine. Hoping you got it figured out and could give me some insight? 🤞

Originally Posted by wretched73

Well.... the timing was off.

I installed the cam dot to dot. Then after these issues I reset the cam with a degree wheel. After that it fired up without any issue. I'm just happy it wasn't too far out and there was no PTV issue

Originally Posted by Stepside Silveraydo

damn, i haven't had my engine apart so i doubt its that. Ive been chasing my tail it seems and can't figure it out. But I'm glad you got yours sorted