Fuel pump not pumping on b210

[Alex B210]

I 'm stumped with this one. 1976 Datsun b210 with an A12 engine.

I've disconnected the fuel pump outlet and put a container on the outlet line and no gas gets squirted out when I turn over the engine with the starter. I've taken out the fuel pump and when I manually engage the fuel pump arm, fuel that was inside the pump gets squirted out fine. I've even tried with a spare fuel pump I had and I get the same issue. Could it be the rod that pushes the fuel pump arm inside the block somehow? Could it have disconnected from the pump arm? How do you even line that up properly wit the fuel pump? Pump just seems to slide into place when I install it.

 

Car was running perfectly fine a few weeks ago and then I haven't used it for a few weeks and now it won't pump fuel somehow? I don't understand how it could just stop working by being parked a few weeks. My carby's fuel bowl has gone dry. I have about a 1/4 filled gas tank and the car is parked on a slightly back leaning slope if that can affect anything.

Will you please help a dumbfounded millennial Datsun gurus?

[datzenmike]

Run a hose from the inlet side into a container of fuel that is higher than the pump and try it. (be sure to have a container to catch any coming out) It may take a while to suck the fuel from the container. Pull the coil wires off so the engine does not start.

 

Yes there is fuel now..... Your fuel filter may be blocked, or the line to the gas tank. Fuel line may have been damaged. Hose may have a split or hose clamp not tight... the pump will suck air in and be unable to lift the fuel.

 

No there is still no fuel.... and two pumps have been tried, remove the pump and look in the hole using a flash light. Turn the engine over you should see the eccentric or lobe that pumps the fuel pump arm. Very unlikely the cam lobe suddenly disappeared. 

[Alex B210]

Thanks for the reply Mike!
I did as you suggested and isolated the fuel pump from the other lines. sure enough it was pumping fuel properly that way. 
So I blew some air in the fuel filter and the lines around the engine bay and the air flowed smoothly all accross. 

It started instantly when I reconnected everything so I'm guessing it was probably some loose hose clamps as you hinted at.

Thanks so much for the help!

[datzenmike]

If the fuel filter hasn't been replaced in the last 3 years, or you don't know when it was I would replace it. They are only a few bucks. It would be the first thing to collect sediment. As you've cleared the block, carry the new one and let the old filter collect and plug up first.