no fuel in the carb

[chris989]

Hello all,

Somewhere i was reading about this problem and now i have it and can not find the old link.

78 f250 400,

I changed the fuel line from the tank switch valve to the pump with all rubber/braided line. The metal was too close to the header and causing vaporlock issues but other than that it always started in an instant.

Now with the rubber hose, if the truck sits for a day or two i have to crank the motor to pump fuel back to the bowl.

I can not see how it can syphon back out of the carb???? Anyone have this issue? This is my first desert summer with the truck (100+ already), could the fuel just be evaporating out of the bowl??

chris

 

[dustybumpers]

You have an air leak somewhere between the fuel pump and the tank. She's sucking air, and loosing the prime

 

[smokey]

I agree with Charlie sounds like a air leak somewhere.

 

[chris989]

You have an air leak somewhere between the fuel pump and the tank. She's sucking air, and loosing the prime

I will go back and retighten the hose clamps then go from there.

thanks

 

[fatheroftwo]

I have the same problem,

and was told to put a spacer between carb and intake. It helped, but after sitting a day or two, hard to start, would an air leak not also leak fuel?

I have an inline fuel filter just before the carb, and when I shut down the engine, it begins to bubble. i also have an inline filter before the fuel pump, and it is usually 1/2 full.

I am still trouble shooting my truck for this, and any and all help is appreciated.

 

[chris989]

and was told to put a spacer between carb and intake. It helped, but after sitting a day or two, hard to start, would an air leak not also leak fuel?

I have an inline fuel filter just before the carb, and when I shut down the engine, it begins to bubble. i also have an inline filter before the fuel pump, and it is usually 1/2 full.

I am still trouble shooting my truck for this, and any and all help is appreciated.

I finally squeezed my truck into the garage with deflate stock tires so i have not been driving it. I am going to go through the axles in the next few weeks.

The bubbling after shut down is most likely because the small pressure of the pump was increasing the boiling point even at just a few PSI. If it is boiling in your filter, it is boiling in the bowl.

From other cars in the past,,,, I am leaning towards the gas boiling/evaporating off after the engine is turned off. Here in las vegas it is already 110 today and 10% humidity which does not help either.

Gas just evaporates out through the vent.

When i upgrade my cam and intake i will definitely block the exhaust from heating the runners and install a heat shield under the carb.


chris