Ok so I've got a 2010 Lmm im working on and can not figure out what the problem is. The customer bought the truck with a cracked piston. Pulled the motor out, bought fingers pistons for it, has the bottom end rebuilt by machine shop. I assembled everything from the short block up. Carillos, girdle, fingers, main studs, head studs, 66 over s480 billet twins, 60% over exergys, Ats twin cp3 etc etc. I made a fuel system with two fuel manifolds just like I used to have on my built 03. Got the truck put back together and running and it fuel smoked some at idle, a lot while driving but the tune was for a vgt high pressure turbo so I figured tuning was a big part. Had tony retune the truck and it ran great (still smoked more then I thought it should with 60's ) but ran strong and pretty smooth. Now after probably less then 100 miles the customer says he was half throttle and something made a noise kind of like going into allison limp mode. And now the truck will start and idle fine(fuel smokes) but it will not rev over 2200 rpms. It starts missing and shuddering almost like a studder box per say. So far I've removed the pickup assembly in tank checked for cracks/ sucking air. I've redone all the Airdog lines because they were previously routed all over the place. I've checked fuel pressure at the fuel blocks and have 10psi constant. I've taken the injectors and had them all tested. Two of them supposedly had something going on internal letting fuel bypass. I figured that was the issue. Nope. Put it all back together tonight and absolutely zero change. If I make it spit and sputter long enough it will throw misfire codes on multiple cylinders but it has no electrical fault codes. Checked wiring. Sorry for the long winded thread. Any help is greatly appreciated I'm at a loss here.
Been there before. It's a real crap shoot these f'in cranks!