I have a 1988 Ford F250 7.3. It starts fine and will idle all day long, but when i drive it it wants to die. I can low idle around at like 15mph in 2nd, but if i get into it and upshift it starts cutting out, starts smoking, and it dies. I just replaced the lift pump, it has new injectors, and i had a mechanic look at it and he said the injection pump was fine. Can you help me?

 

more info, and also post this down in the 6.9 forum. how many miles, auto or manual, dual fuel tanks?

 

somthing restricting flow? filters? is there a lift pump? rotten rubber hose letting air in the system