I've been reading through the archives and can't seem to find the answer I need.

On my 84 Crew with the CTD, now is it supposed to have 2 fuel pumps? One in the tank (electric) and one off the motor (manual-piston pump)??

I know I have the manual one on the motor, but should I be able to hear the one in the fuel tank, if it is there and hooked up?

If only running the manual lift (fuel) pump off the motor will there be any problems? Or should it have an electric unit as well?

Thanks for the help and education....

 

You only need the Lift pump on the engine.

 

There is no other one. A few fellows have a high flow electric pump in parallel with the manual one, they keep the manual one in case of an electrical failure. The best way to keep electric pumps happy is mount them close to the tank (NOT on the engine like the 24v's that rattle them apart), and have nice, oversized piping.

 

Thank you for the help guys, I was a bit nervous that I might be doing harm to my motor.

Now is there any problem running the original unit, or should I consider an aftermarket upgrade unit. I don't plan on doing any big mods to my motor, 3200 Gov spring, maybe 16mm turbo and an intercooler, that's about it.

 

Original is fine till it dies.

 

Confusion sometimes develops when on some conversions the fuel-tanks on the chassis used will have in-tank electric pumps.

I doubt that is the case with your combination.

You should have an engine-mounted mechanical "diaphragm" lift-pump as originally supplied on the 1st Gen. Cummins; there should be no lectric pump in the tank.

A good upgrade is a 3936320 low-pressure piston lift-pump = still a mechanical pump, piston operated instead of diaphragm.