RangerDan

I tried this in the tuning/diagnostic forum, no dice, so I'll try here:

Hey guys,
I've done a lot of searching and have come up pretty empty-handed so I'm gonna see if any of you have an idea of what else I can try.
I have a 2008 Sierra 1500 with 5.3, non-flex, AFM. Last year, I hydro locked the motor and bent a rod, so over the summer my father-in-law and I pulled the motor to replace the rod. I figured if I was already going that deep, I may as well have some fun. On top of replacing the bent rod/piston/bearings, we pulled all the other pistons to clean them up and deglaze the cylinder walls. I did an AFM delete (solid lifters) as well as a TSP 220 cam swap (kit) and new NGK Platinums. I crashed my motorcycle in the summer, so my father in law finished putting the motor back together and into the truck for me, and I've been working on tuning with Justin and I've been struggling to diagnose what my issue is. Now, for awhile it ran alright, then slowly started getting worse. At first, it just wasn't firing on all cylinders, and lately it's gotten to the point that it's incredibly hard to start and when it does, it runs like crap (maybe 4 cyl firing). Justin said it looked like bank 2 wasn't firing, so I went to work there. Cold compression test gave me numbers all around 120. I've checked for vacuum leaks by spraying carb cleaner, no change. If I get it running and spray some carb cleaner down the vacuum line, it seems to clear up for a bit and all 8 cylinders fire and while that happens I've unplugged the injector and the coil for each cylinder and listened for a change in the exhaust note (I can hear the "cough" of a cylinder not firing). The only current code I have is an 0446 for my EVAP, pretty sure it's the solenoid but I haven't changed it yet (I don't see how that would affect this?) I've pulled the plugs and it looks like they're running on the richer side of things. I took it for a (fairly short) drive once after doing the cleaner through vacuum line trick and it ran well for the first leg, but after stopping to pick up a couple things, it was a fairly hard start again and it was no longer firing on all 8. I'm starting to lose my mind here, I don't know what else it could be? Thanks guys!

Dan