The Humvee takes off on its own like if someone flipped the "After Burner" switch.

[Tiwaz]

The problem is that going at a steady speed, say…. 30 mph without changing the pressure applied on the gas pedal, all of a sudden the truck (1151) behaves like if I floored the pedal, it even downshifts on it’s own and takes off, and if I keep the same pressure on the pedal, it reaches about 50 MPH (or more) and it stays there for 10-15 seconds and then it behaves like I removed the foot from the pedal all together and it goes back to normal.
It does this even at 50 MPH the only difference is that it does not downshifts but you still hear the engine revving up and the speed increases substantially.

 

[Mogman]

I do not believe "Humvee" and "afterburner" have ever been used together before

 

[NDT]

Is there an animal curled around the injection pump?

 

[Tiwaz]

Is there an animal curled around the injection pump?

hehehe... no... the only animal present is behind the steering wheel

 

[NDT]

If you have a way of verifying that the injection pump is doing this on its own, as in the control shaft isn’t rotating, your injection pump is crapping out internally. Time for rebuilding.