1999 C-2500 Runs Rough

[gm88]

I have a 1999 c-2500 with the 5.7 and 4l80e with 100,000 miles. Today when sitting at a stop light the truck just started running really rough like it was missing on 1 or 2 cylinders. Anyone have any ideas abt what can cause this? I put plugs, cap, rotor, coil and dist. on 6,000 miles ago(to correct sth else, which it did ). New MAF 12000 miles ago and fuel pump is not original. I plan on checking fuel pressure tommorow after it cools off and checking for any loose/damaged spark plug wires. Also today when i got home i could smell raw gasoline with the hood open and it idiling. After shutting truck off the gas smell quickly went away and i didnt see any on the ground. While sitting in park the truck will idle very rough and miss, however, i can rev it to 2500 (didnt try any higher) and it seems to smooth out, or at least be revving high enough to not feel the miss. Any Ideas?

 

Thanks!

[Prokopchuk_9]

check cat's out...no codes???

[jstrong71]

I have the same issue. Did you ever narrow it down?