This past Thursday & Friday I was hauling some tires (130 semi truck & a dozen or so car/truck tires) . On my second load (30 semi), I was going along around 45-47mph just fine & the motor seemed to just open up. I backed out of the throttle to keep at or under 50mph. The Friday it did it several more times at different speeds & rpms. Best I can figure is something inside the injection pump is moving around on me.


My fuel system isnt stock. 13gal. steel tank on the frame > little steel screw in filter on the Mr Gasket green diesel pump > a clear plastic mesh filter where the OEM water separator goes > under motor, bypassed the mechanical lift pump to the OEM filter head & the rest of the system.

 

You have a fuel supply problem. Maybe lift pump sucking some air or down on performance.

 

Could be. I have a PM2 coming up soon, might just do it early anyway since I gotta change the r/s valve cover.

 

definitely sounds like its sucking a little bit of air. a few months ago mine started leaking from the water seperator - it was dripping after i turn it off, and sucking air while running. when it wanted to, it ran like nothing else, and when it wanted to it returned to normal. i sealed up the leak redneck-style and it hasn't happened since. not saying thats where your problem is, but thats definately the type of problem you have
it might be helpful to apply LOW pressure to your entire fuel system and look for any leaks.

 

I know of a small leak around #4 injector but it is barely damp. Honestly I want to redo the whole fuel system from tank forward & back. New hard line & rubbers but $$$ & the fact I still need to get my wifes car going so I can drive my other truck.