I have an 89 F250 4WD 5SPD Heavy-Duty with duel tanks 5.8W Fuelinjected. When I try to start it it will run for about 5-10 min and start to sputter and stall. Then it will not run until it has sat for about 15 min. it will try to start but won't. Then it will do the same thing all over again. I put a new high pressure fuel pump in, new fuel filter, and both relays in. I am not getting a consistant pressure reading on the fuel rail (never over 30psi). Both low pressure pumps are working and it does this with either tank. Any help would be greatly appreciated. Thanks Gary276

 

How are you getting the 30 PSI reading?
Did you have pin #6 of the self-test connector grounded with the key on and the engine not running?

How do you know both low pressure pumps are working?
Did you take their pressure line off at the selector valve and stick it in a 5 Gal. bucket with pin #6 of the self-test connector grounded with the key on and the engine not running and that tank selected?
If so what was the pressure reading and how did it pump in one minute?

 

The only way that I checked the pumps in the tank was by grounding the test wire and listening to the tanks. I did not remove any lines from the selector valve at all (yet). The pressure readings that I have been getting have been with the truck running.

 

Ok with it idling pull the vacuum line off the fuel pressure regulator and see if the fuel pressure goes to about 40 PSI and that no fuel comes out of the regulator nipple. If fuel comes out the regulator is bad.

 

I will try that tomorrow. Truck is at work. Thank you .