Truck runs great but has a surge feeling when running 70-75mph and ease off the throttle, if throttle is completely let off, it does not do this. Lift pump issue or injector pump? Factory replaced lift pump with an updated one about 1 1/2 yrs ago. Truck blew a fuel line on injector 5 and after that was fixed is when i noticed this surge. Thinkin it is pump issues but not sure. If I do a replacement, what all should I replace when doing the fass or raptor swap?

 

any suggestions out there?

 

it does not do this issue during take off or under hard acceleration, only when cruising and need to slow down a little.

 

lift pump went out on me yesterday afternoon on way to truck pull. had it towed to dealer. If for some crazy reason they don't warrenty it, it'll get a FASS

 

I have not had that issue but I replaced my factory lift pump with the airdog. The install was not too bad and the mistakes I made could have been avoided by reading Willys43's post before install instead of after.

Either way, if you do anything other than commuter driving, a better lift pump is a must. Mileage increases and fuel delivery is much more reliable.

 

thanks, maybe i can figure it out

 

A fass system is a must on any dodge diesil. The factory pumps suck. I don't know much about the other pumps but I have exprence with the fass pumps and they work well.