I have a 1989 f250 fuel injected duel tank that wont start. what is that blank cylinder looking thing on the frame. there is six hoses goin to it. i believe its the switch to change between pumps but im not sure. there is no wires going to it so i dont even know how it works. What is it and how can i bye-pass it if possible?

did you replace low pressure pump in tank, There is actually a low pressure pump in each tank and a high pressure pump inside the drivers side frame rail about right under where the driver sits.

if the fuel lines have any rubber fuel lines they could be sucking air. also try replacing the fuel caps, it may not be venting

There is a fuel pump reset switch under the dash near the lower heat ducts at the floor.i think on the drivers side but it has been a long time since i done this.

all fuel injected vehicles have an electric fuel pump inside the fuel tank.On ford F250 there is 2 ,one in each fuel tank

I have 2 1989 GMC S-15 trucks (actually one of them i bought for my daughter). Anyway, the 2.5 four cylinder one has the fuel filter on the firewall between the brake master cylinder and the engine. The other one is a 4.3 six cylinder and the fuel filter is on the inside of the frame rail on the driver's side, kind of under the cab near the fuel tank. Hope this helps.

the filter(s) should be under the truck along the frame rail towards the rear but in front of the tanks

You have duel tanks with a fuel pump in each tank. You also have a fuel pump on the frame rail after the "tank selector". This device only holds a fuel filter that protects the main fuel pump. When you select front or rear tank on the dash, you are selecting which in tank fuel pump will operate. You can check the in tank fuel pump by listening for it to "humm" when the key is turned on..The in tank pumps only feed the main pump and cannot run the engine on their own. Hope this helps

the filter is located approx under the driver on the inside of the frame rail, I think you have plastic fuel line retaining clips in this year, so no tool required. see photo

Hey lets try this ! Locate your starter solenoid & look for a yellow wire marked with a "W" . That may be the fusible link for fuel pump. Let me know what you find.

Carburated engines is on the drivers side of the engine in the front Fuel injected are in the Tank and some high pressue system had an additional "pusher pump" on the frame rail