LS2 intermittent backfire through exhaust when cranking

[FTK]

Any help would be greatly appreciated. Tuned an ls2 speed density in a Nova and the tune went normal, ran perfect and made good power. The next day I went to start it and it sounded like a distributor was out 180 degrees..popping and banging during the crank. Shut the key off and tried again and it fired normal. The next 15 starts it was fine then it will act up again. When it starts it runs perfect. Has a new computer and wiring harness, checked all connectors and even replaced the crank and cam sensors with no change. Any ideas?

[bpm]

...

[lukearmstrong1990]

what PCM and what did the cam gear look like on the front face?

[ECM327]

i have a 2000 turbo truck that does the same thing ! maybe a crank relearn or not enough priming fuel or bad ground or voltage problem? if i key it on 2 times it fires right up usually most of the time . just my thoughts .have not had a chance to dig into since i do not drive it very much .
also my battery is just little on the low side. it would not start the other day popped thru the exhaust couple times then would not turn over starter clicked .hooked jumper cables up to it hit the key and it fired right up hth

[ZachCopeland]

Had a similar issue on a p01 pcm. Would start great directly after flash drive around turn it off and go to restart nothing pop pop bang bang suck suck nothing. Then after 5 or so try it would find itself. Got to looking in the harness and found the wire for pin 75 (pcm ign, run, crank power) was missing and this was a standalone harness from a pretty decent size company. Placed the wire in the harness and bam she fires first hit. Not saying yours is missing but might possibly be a bad connection?

[jason_at_rpm]

i would look into cam and crank sensors. i had a very similar issue with a gen 3 truck with a gen 4 engine with an extension for the cam sensor and it was wired incorrectly and killed the sensor. fixed the wiring and installed a new cam sensor and all was good