Mech Fuel Pump 318

[old_chrgr]

I just replaced the fuel tank, and now I can't the fuel pump to, well, pump. I changed it out 2x before I replaced the tank, and figured they were ruined by varnish, rust bits, etc. from the old tank. But the new one put maybe a teaspoon into the new filter, then quit. It won't even pump gas with the line from the carb disconnected and inserted into a bottle. Oh, and I flushed the line from the pump to the tank with carb cleaner before I re-connected it.

Any ideas? Surely a new pump right out of the box should work, right?

 

[krandall]

I'd tend to lean towards a bad pump but.. a few things to note.
The best way I've done it is dump some gas into the carb and get the engine fired.
It pumps the fuel pump way more than just cranking.
Otherwise, can you pull the line from the fuel pump that goes back to the tank and blow in it to hear bubbles in the tank?

 

[old_chrgr]

I'd tend to lean towards a bad pump but.. a few things to note.
The best way I've done it is dump some gas into the carb and get the engine fired.
It pumps the fuel pump way more than just cranking.
Otherwise, can you pull the line from the fuel pump that goes back to the tank and blow in it to hear bubbles in the tank?

Actually I did think of that, but instead used a hand pump to suck some gas out of the line... I guess I'll try another pump...still seems unlikely but I can't think of anything else... Thanks for the reply bud.

 

[krandall]

Yea, I'd find that extremely odd as well. Another option.
You could try a setup like this just to validate there's no crud in the carb blocking total flow.

(bottle with gas) -- (tube) -- (fuel pump) -- (tube) -- (empty bottle)

Otherwise I'd go down the path of the fuel pump, good luck!!

 

[old_chrgr]

Yea, I'd find that extremely odd as well. Another option.
You could try a setup like this just to validate there's no crud in the carb blocking total flow.

(bottle with gas) -- (tube) -- (fuel pump) -- (tube) -- (empty bottle)

Otherwise I'd go down the path of the fuel pump, good luck!!

I tried the empty bottle part, but not the bottle with gas. Good idea, and it won't take much to do. Thanks!

 

[condor74]

I am with you that having multiple pump failures seems unlikely. I would put gas in the carb to start the car while placing a vacuum Guage on the pump inlet. If you are not pulling any vacuum then you know the pump is not working.

Now just thinking out loud but did the car run at all before you cleaned the tank?
Is it possible that the timing chain or gear has broken and is causing the cam not to spin there by not pumping the arm of the pump?

 

[old_chrgr]

I am with you that having multiple pump failures seems unlikely. I would put gas in the carb to start the car while placing a vacuum Guage on the pump inlet. If you are not pulling any vacuum then you know the pump is not working.

Now just thinking out loud but did the car run at all before you cleaned the tank?
Is it possible that the timing chain or gear has broken and is causing the cam not to spin there by not pumping the arm of the pump?

Condor - love the handle - yes, it did run, and after another pump it did fire up! Thanks for the reply. I still can't believe the pumps I went through. All I can figure is parts sitting on the shelf for years waiting to be sold... Before I took the last one home I did suck and blow (gently) on the inlet and outlet to see if there was a little resistance. The old ones I ran through had *zero*, which suggests to me that the check valves or diaphragm weren't working... Wish I'd thought of that earlier