Hey guys,
The short version of the story is I did some work for a buddy's shop over the winter because he was short staffed and overloaded with work. A customer brought in a LS 454 "turn key" motor built and sold by a reputable national speed shop and he wanted the us to swap it into his late model pickup. I have done plenty of engine swaps including 3 LS style and the shop owner has done countless.
Motor and trans went in fine, the only issue we really had was the harness supplied did not match the LS7 map sensor. We called the harness manufacture and they sent us a new pig tail, said it was a direct fit.
The ECU came with a basic tune so we had an email tuner build us a performance map. We have used this tuner multiple times with no issues are they are recommended by the motor builder.
It took 5 tunes, but the truck now starts and idles, however we are still getting a random missfire under any sort of load and when it does pull to past 3k it does not feel like like a 700hp big block, not slow, but not impressive. The tuner has basically thrown up his hands and says its not the tune, the speed shop says its not their hardware and I have checked and rechecked the install and found no issues.
Checked or replaced
Fuel pressure, rock solid at 58-60, volume is good
resistance on all plug wires-good
swapped in new coils (no change)
smoke tested intake track (no leaks)
new race fuel
grounds\powers\wires no obvious issues
Engine specs:
LSx 454
11.45:1 compression
OEM LS7, Map, Intake, TB, rails and injectors
06+ Z06 OEM MAF
LS7R Cam 248/260, .657/.655 with 1.8 ratio rockers, 111 LSA
Bowler 4l80e (not sure of the TC stall but its feels low...noting super aggressive)
Customer has ALOT of money in this and we want to make it right for him but have run out of options.
Can you please look over the tune and log and see if there is anything we are missing.
thanks
Shea
454ss log file 7. best yet.hpl
454ss installed tune 6.hpt
454ss log file 6.hpl