Farm Trac 390 HST 4 cylinder Mitsubishi diesel engine electric fuel pump pressure

bcribb · Aug 22, 2018

I'm trying to find out how much pressure my electric fuel lift pump is supposed to have. Its a 390 HST Farm Trac 4 wheel drive tractor.It has a 4 cylinder Mitsubishi engine. My tractor is bogging down under a small load. Fuel line is clear from the pump to the tank. Has a new fuel filter and recently cleaned injectors. The tractor has always had this problem but seems to be worse now. When I pull my rake up a slight incline the engine will bog down and sometimes shut off and then its hard to start back up. Any help on this problem would be greatly appreciated..

nyone · Aug 23, 2018

That does sound like your lift pump isnt pumping enough GPM/psi. Next time it shuts off turn the key so the pump comes on and let it run for about 30 seconds. If it starts right up you need a new lift pump.

Or you could just throw one in anyway. There about $35 from airtex.

thepumpguysc · Aug 24, 2018

Really depends on what type of injection pump it has..
IF its the small inline PFR pump that sits down inside its own "cradle" on the engine?? it needs about 10 psi at the inlet.
If its the larger inline pump that bolts up to the engine block & is gear driven.. it needs 25 psi at the inlet to run properly.
IF its the small rotary pump that bolts up to the engine block & is gear driven, it only needs 1-3 psi at the inlet & is usually gravity fed.. but a lot of people put electric pumps on them.

bcribb · Aug 24, 2018

nyone said:
That does sound like your lift pump isnt pumping enough GPM/psi. Next time it shuts off turn the key so the pump comes on and let it run for about 30 seconds. If it starts right up you need a new lift pump.

Or you could just throw one in anyway. There about $35 from airtex.

Thanks, I try to figure out which pump I need, 4 lb or 12 lb

thepumpguysc · Aug 24, 2018

I just looked at your other post about the solenoid.. You have a PFR pump.. the one that sits down IN the engine block.
Gonna need the 7-12psi.. A 25psi will be WAY to much & you stand the chance of hurting other things.

bcribb · Aug 24, 2018

thepumpguysc said:
I just looked at your other post about the solenoid.. You have a PFR pump.. the one that sits down IN the engine block.
Gonna need the 7-12psi.. A 25psi will be WAY to much & you stand the chance of hurting other things.

You have helped me so much and I appreciate it. Where can I get a 7-12 lb pump. Thanks