Engine/Transmission (1994 - 1998) Lift Pump And Injector Pump

[radar doctor]

son has a 96 standard Trany, we are wondering if these units had any Lift pump Problems and if there were many Injector pump losses... He claims its mechanical and wont have problems, i was thinking that they had these problems. . Can anyone strighten us out? thanks Bill

 

[Joe G.]

Lift pump and injector pump problems are rare for a 12 valve. Air leaks in the fuel system are a problem. Many times the lift pump is replaced because of an air leak when nothing was wrong with it. If there is a fuel system problem so that the injector pump is starved for fuel the engine will quit, but the injection pump is not damaged like it is for a 24 valve engine. My '95 has 139K miles on it with the original lift and injector pumps. I thought I had a lift pump problem once but it turned out to be an air leak in the fuel heater.

 

[jjohn]

I believe the 96 p-pump truck has a mechanical lift pump that runs off a lobe on the cam shaft as my 1st gen truck had. I don't think there is a issue with them like the electric carter lift pumps on 24 valve trucks.

My 1st gen 1990 truck went 189K with the original mechanical when I sold it.

 

[Reb.B]

Well the lift pumps will go out, but not very often. They usually go out when you prime them outside, and the seal goes bad. If and when it does go out it will Not take out the injection pump. The 94-early 98 is a mechanical pump and it is lubricated by engine oil, Not diesel.