Technical Sputtering fuel pump

I recently replaced my fuel pump and had trouble starting. Finally filled up the float bowl through the vent tube and got it running for 30 seconds or so. Then it cut out again...

So I took the fuel line off the carb and did the same thing.

This time it ran for about the same amount of time, but the fuel line was just sputtering fuel, not a steady flow but bursts of air mixed with a little bit of gas.

Is this new fuel pump bad or is this an indication of a clogged line? Or air in the line?

Thanks

 

i wonder if your fuel line is clogged between the fuel pump and the fuel tank

 

Could be:
1.Crud floating around in the tank that clogs the flow.
2. Non-vented gas tank.
3.Clogged fuel filter, if you have one.
4.Flexible fuel line hose on firewall is collapsed on the inside.
5. Cracked or leaking fuel line from tank.
6. Disconnect fuel line at carb and blow air thru gas line.
Use a separate gas container to supply fuel instead of the gas tank and see if carb gets gas
and engine runs better. If it does, you probably need to clean out your gas tank.

 

Was it the exact same conditions before you replaced the fuel pump ? One possibility is check your fuel sending unit attube. I had one that rusted and had a small pin hole that created the same type of problem. Also check the screen in the fuel pick up tube inside the tank. They can get in bad shape. Check fuel line for cracks causing to **** air.

 

It was #4. It looked old but I didn't think about it since I was running fine before. Wrestling it off the old pump must have busted it enough to kill all flow. A new hose ($20 at Napa) fixed the problem and now I'm running again.

Thanks for all the help, as usual.

 

Mechanical fuel pumps do not give a steady stream.

 

What kind of engine---What kind of fuel pump?

 

Problem is solved with new hose from fuel pump to sending line. Thanks

 

Glad you fixed it , and came back to tell us

 

Hey, Noobee here. I just got a 41 super deluxe at auction. Flathead V-8, 2 distributors, positive ground, crazy stuff I’ve never worked on.
She ran good, 30 seconds, a minute, black crud fills the gl*** bowl and she dies.
Ok I had the tank boiled out and coated inside. Bed liner outside. Fuel line blown out.
Carb linkages didn’t look like the ones on YouTube so I “fixed “ that.

Now, clean gas fills the gl*** bowl. Not a drop leaves the fuel pump.
Does this diaphragm look ok? I mean should it be as separated from the metal plate as it is?