First post,
I got a 92' w/ the 302 EFI 5.0 and it had 171,000 miles on the odometer.
after 6 months i'm at 174,000+ miles and ran into a fuel issue.
The truck started bogging down while driving due to a lack of fuel.
I switched to the front fuel tank and the problem was resolved.
I drove on one tank for a month and reluctantly switched to the rear tank.
The truck drove me to my destination with no issues.
When leaving my destination the issue ensued, but now with BOTH tanks.
I have replaced the fuel pressure regulator AND the fuel filter, and the problem still exist.
When I switch the key in the on position, the fuel pump primes, but at a lower tone than before.
When I switch between the two tanks, both prime when trying to start.
Also when the pumps were primed, I checked the release valve on the fuel rail, and only air with a slight bit of gas came out.
Any information would be appreciated.
Thank you

 

 

Sounds like you need a fuel pump... check it with a pressure gauge at the Schrader valve.

 

damn, that's strange both pumps went out such a short period of time..

 

Did the unused tank, I believe the rear, mysteriously fill itself up during this time period? Your problem could be the all too common failed check valve in the rear tank. It can stick open enough that even though the front pump is running there is not enough fuel to run the engine. Most of it is diverted to the unused rear tank.

 

You have two in tank pumps and one high pressure pump along the frame.

 

No sir....the OP's 1992 has a high pressure pump in each tank. There is no external high pressure pump. Ford stopped using the fuel system you are describing after the 1989 model year on the F series trucks.

 

I stand corrected....

 

I disconnected the fuel pump connector at the tank and checked power at the connector with a volt meter KOEO and had 6.6 volts this matched what was at the inertia switch. I get 10.6 volts engine cranking. I then sent 12 volts into the pump to see if the pump would start (red&orange wires)and nothing happened at the front tank and the rear tank pump clunks but doesn't run. I am going to drop the front tank and have a look with a new pump on hand.

 

A little deeper in and I find this. I would have to replace both tanks and pump sending unit assemblies. Probably not worth it here as parts are hard to get.

 

Old red.

I replaced both tanks with new ones that had pumps and all in them. So far it runs good. It has nor ran in many years so I am happy with it working for now.