slowrollin93

iTrader: (7)

I have a 04 ls1 swap in my 00 silverado, truck intake stock 241 heads, it runs like it's missing. Mods are lts, cai, mtr1 cam. Checked pushrods and valve springs, all 8 injectors firing, all 8 plugs firing, fuel rail pressure is 55 at idle 61 or 62 when cracking throttle open, new plugs and wires, new fuel filter, tried switching PCMs didnt change anything. When you give it very little throttle it's fine, but if you give it more than say 10% it sounds like it's missing and barely back firing. Ran fine after cam swap and that was maybe 6-7k miles ago. Here is the thing that makes me think it's the map sensor. I had one go bad before when I still had the 5.3 and it ran kinda crappy but when I sprayed nitrous it acted like it does now when you go wot. Also I unplugged the map and went around the block it ran the same as it does now, made absolutely no difference maybe even ran just a little bit better. I have been spending money guessing and I would just buy one and see if it changed anything but we just had our daughter and I want to be sure before I throw $50 at one.

Thanks
Jon