I have had this truck now for just over a year. 200k plus miles ........
Has done great untill recently my muffler came off while coming out of the woods from work (oil field work); {also the converter was off when i got it} I ran it for 2 days befor I took the time to get a new clamp and put the muffler back on. That same day as I was heading home it started loosing rpms and sputtering like it wasnt getting fuel. I could pump the pedal and the more i tried to rev the engine the more it wanted to kill it. If i pump it in quick strokes it woould increase rpms. If i put it in nuetral it would rev fine and the if i let it gradually run it would build rpms but not all times.
Seems to run better at lower speeds but runs like junk 50 to 70 mph.

I have done these things and still no fix. I put it on the computer it showed cylinder 8 and 2 bad and an o2 sensor (wich i expect since converter is gone)
But I was talked into putting a fuel pmp on so i did. NO HELP!!!! I put new plugs and wires in and the cylinders codes went away but still no fix....

Anyone heard of this before? Any help?

 

Check the coil?