I've recently purchased 78 F-250 with a 460 V-8 (or so I've been told). I purchased the truck to be my "Farm Truck" and I don't have a lot of previous experience working on trucks.

Shortly after I purchased the truck, I couldn't get the engine to start. The starter would crank all day long, but eh engine would never catch. If I sprayed starter fluid into the carburetor, though, the engine would catch immediately, then die.

I assumed this meant I had a fuel pump problem, so I unhooked the fuel supply from the carburetor and fed the hose into a jar. After cranking on the starter for a few minutes, I looked in the jar and saw no gas. I removed the fuel filter and tried the same test -- still no gas.

At this point, I assumed that the fuel pump was not pumping properly so I removed the pump (located on the front-right side of the engine) and sure enough, the spring on the pump lever was sprung, so the pump lever never returned to it's start position.

I replaced the pump and tried again, but I'm still not getting any fuel through the pump. I figured that perhaps I had installed it incorrectly, so I pulled it off again and it appeared to be installed properly.

Then, I tried some other troubleshooting techniques... I tried to pump (manually) the lever with the pump connected to the fuel supply line and was not able to get any fuel to flow through the pump.

I also tried to cover the inlet port on the fuel pump and manually pump the lever, but was not able to feel any suction on the port...

Were these valid tests? Do they indicate a bad fuel pump?

Are there any other tests I should try?


Thanks in advance!

Greg

 

Try running a hose from the pump's inlet port to a small container of fuel, and another hose from the outlet port to another small container. Then work the pump arm and see if you can move the fuel from one container to the other. If that works, the pump is probably ok.

If the carb sat dry for a long time, the inlet needle valves in the fuel bowls could be stuck closed, keeping fuel from entering the carb. You might need to (at least partially) disassemble the carb and make sure the inlet needle valves aren't stuck.

If the pump is ok and the carb's inlet needle valves are not stuck, then you need to check the fuel line from the tank to the pump. Examine all the hard (steel) lines for kinks or cracks, and replace all the rubber lines. Replace the hard line if it is damaged.

Inside the tank is a sock-type filter on the fuel pickup tube. That could be clogged. If you know the pump is ok, and all the lines are good from the tank to the pump, the problem could be inside the tank. In that event, you'll have to drop the tank and open it up to check things out.

Once you eliminated all the problems upstream from the pump, start going toward the carburetor. Check the hard line and replace any rubber hose sections. Replace the hard line if it is damaged. Install a new fuel fiilter.

 

I agree, it could have a dry rotted rubber line going from the tank to the metal line on the frame and could be sucking enough air that it will not pick up any fuel out of the tank.
Jimmy

PS. You sure that it has enough fuel in the tank to be picked up by the pick-up tube?