Lost my prime,

[gray gables]

Had to change out my fuel filter an o rings cause the crappy gas we have rotted them out. Well it had been a month or so since I got a chance to replace them. I had taken out the old an I'm wondering if that made me lose my prime. I installed the new filter and rings and now I can't get the gas to flow. Nothing in my filter at all. How do I fix this?

 

[tasker]

you sure you fuel pump is good? lever on the pump only works while cranking

 

[smokinjoe]

Pour some gas directly in the carb to start it and get that eccentric a'spining. Like Tasker said, the pump ain't pumping unless the motor is turning.

There's a round fuel pump eccentric that bolts to the end of the camshaft, that eccentric pushes down on the fuel pump arm every cam revolution.

 

[SavageBurro]

If you have the ole 2bbl - fill the bowl with gas:

The top of the carb comes off very easy:
Remove the air cleaner;
Remove the clip that holds the choke arm;
Remove the four little bolts holding the top on.

Fill the bowl about half way with gas.
Gasket is usually re-usable for several removals (or install a new top gasket)

Reinstall.

Should fire right up and run long enough to prime from the tank again.

 

[gray gables]

If you have the ole 2bbl - fill the bowl with gas:

The top of the carb comes off very easy:
Remove the air cleaner;
Remove the clip that holds the choke arm;
Remove the four little bolts holding the top on.

Fill the bowl about half way with gas.
Gasket is usually re-usable for several removals (or install a new top gasket)

Reinstall.

Should fire right up and run long enough to prime from the tank again.

yes, 2 brl carb is what I have.

 

[samamarshall]

The old cup of gas w/ a slow pour into the carb can work to keep it running - don't catch yourself or truck on fire though - better option is to fill carb bowl.

My fuel selector switch and hoses were rotted and garbage, which made the lines empty if it sat for a while, lines sucked in air and fuel ran back to tank (or onto ground!)

 

[SteveL]

Depending on filter make sure you didn't install it backwards

 

[gray gables]

Depending on filter make sure you didn't install it backwards

no, I made sure of that.

 

[gray gables]

spent 4 hrs today trying to get my rig running. I finally got fuel into my filter. After that it would go. I'd fill the bowls with gas, it would start but as soon as the gas was gone it would shut off. I'd had to put a new diaphram kit on, that didn't solve the problem. I can't get any gas into the carb itself. I'm totally perplexed at this point.

 

[bmc69]

I've replaced or rebuilt no less than three fuel pumps and rebuilt at least 4 carbs in my "fleet" of older trucks in the last year. The damage ethanol causes is simply brutal.

Specifically relating to the EB fuel pumps, ethanol makes the rubber seal in the two check valves expand and they simply stop working. No worky..no "prime"..no pumping..

 

[gray gables]

I've replaced or rebuilt no less than three fuel pumps and rebuilt at least 4 carbs in my "fleet" of older trucks in the last year. The damage ethanol causes is simply brutal.

Specifically relating to the EB fuel pumps, ethanol makes the rubber seal in the two check valves expand and they simply stop working. No worky..no "prime"..no pumping..

well, I took the fuel line of the hard line coming up from the pump and turned it over an gas came out. So I know the pump is working. I'm scratching my head on this one.

 

[jckkys]

Just an FYI only centrifugal pumps need to have a prime. The diaphragm mechanical and vane type electric pumps are positive displacement and don't need a prime. Just run a hose from the down stream side of the filter to a bottle or jar and crank the engine. If fuel pulses out of the hose, you're OK.

 

[blubuckaroo]

I like to actually test the fuel pump. Connect your vacuum gauge to the suction side and crank away. If you don't do this, how would you know weather you were having a pump problem or a leaky suction line?
By the way, I've seen few bad pumps.

 

[gray gables]

Back at it again today. I took the fuel line off and just cranked away and I have fuel coming out. So I took my carb off and tomorrow I'm going to the shop I bought it from and have them look at it.

 

[blubuckaroo]

Back at it again today. I took the fuel line off and just cranked away and I have fuel coming out. So I took my carb off and tomorrow I'm going to the shop I bought it from and have them look at it.

That won't tell if the pump is OK.
A mechanical fuel pump has to overcome a lot of distance between the tank and pump. There are three factors...
The first factor is, how much vacuum can the pump supply?
The other factor is how much restriction is in the supply line?
Then last, is the suction line free of suction leaks?

Most of the time trouble shooting isn't just a simple pump replacement.
I've seen a leaky selector valve cause enough vacuum leakage to keep the fuel pump from priming.

 

[gray gables]

Looks like it's the fuel pump. Pia,

 

[mudwisr2]

I'm dealing with this as well and agree with all the problems ethanol causes. It's ridiculous. I am going to replace all the rubber lines and should be good to go.

Try running a short piece of fuel line from pump directly into a gas can and see if it will run.