The Stovebolt Site Forums The Parking Lot Big Bolts My 4400 235cid is starving for fuel, help?

Hey Group:
My 4400 sat for a couple of months over the winter. I recently hauled a load of leaves to dump, and on the way home it began to starve for fuel. I limped it home with full choke on.
On inspection, I see that the fuel filter at the carburetor has no fuel in it. I disconnected the fuel line coming from the tank, and it spits out fuel freely, no problems. Also, the glass bulb on the fuel pump is full of fuel. My prime suspect is a failing fuel pump; I thought I'd run it by the group for confirmation. THANKS!

crank the engine with the fuel line from the fuel pump to carb off, disconnect coil wire and see how much fuel comes out if any. on another thought, try starting it again with the engine cold, it could also be vaporlock

Dumb question, but did you run out of gas?

Mike B

Hello pacificnwrider,

Assuming you did not run out of gas, I wonder about the gas itself. I don't know what the situation is in the Pacific Northwest, but in California the "new" gasoline is hard on old rubber and doesn't age well. I put a canister fuel filter in my 66 GMC 5500 truck and let it sit over the winter. In the spring, this filter was plugged by deposits from the gas and no fuel could get to the fuel pump. And I had to replace the old fuel pump because the diaphragm failed, which could have been age or gas effects. In my 64 GMC pickup, which already has a new fuel pump with a modern diaphragm, the new gas is making fuel line hose soft and sticky. And finally, I have been advised not to use the new gas without conditioners in ATVs because it plugs up the carburetors.

One other thought. Did you recently install an unvented gas cap? If air can't get into the tank, removing fuel might eventually cause a vacuum that the pump can't work against.

mine started doing the same thing, I looked at cap etc. and finally found that the fuel line coming off the bottom of the tank had swollen and was not letting any gas through. It was running fine one day, then would start only with the choke out, and run for a bit then die, then finally it wold not start, and it was the fuel line swollen shut inside. As Materman said, start with fuel line off that goes to the carb and work back to the tank.

Thanks a bunch Guys! The sun is out today and I have some time so I'm going to look at those things.

I tried running a bit with the gas cap off. Also, I had just fueled only a few days prior to the symptoms beginning. I should mention that it idles fine, but dies only under driving conditions.

Update: The needle valve in the carburetor was stuck. Its running great now!

SWEET!

Thanks for posting your results! I replaced all my lines last fall, as well as the fuel tank and rebuilt the carb. Now it turns out the fuel pump check valve isn't working and I have to prime the system (run down the battery) if I don't run it every day.

Does anyone know if there is a carb related issue that will drain the float bowl when sitting?

Sounds like it's time to replace the fuel pump.

Depending on how long it sits, the gas can eveporate out.

Mike B

I'm having the same problem, where is this needle valve located?

They're referring to the float valve that cuts off fuel when the carb float bowl fills. On your carb I believe its above the float, at the fuel inlet.

Thanks! The carb is in need of a rebuild so I'm going to hopefully take care of that problem.