Fuel pump problem - need help (1 Viewer)

[Tim71FJ40]

This weekend we cranked the cruiser for the first time after engine overhaul and a complete two year restoration. It started on the first twist of the switch, but only because we were priming the carb with fuel. I had disconnected the line from the tank and dropped it thru the floor and into a gas can on the floor. It's a 71 cruiser with a 79 2F. Although the engine was over hauled and has new cam we used the old fuel pump. I had purchased a new one but it was the wrong one so we used the old one. It didn't pick up any fuel at all.

We took the pump apart and nothing was torn or worn.

Considering just going with an electric fuel pump, but does anyone have an idea of what the problem was?

Thanks in advance.

 

[edwjmcgrath]

If you decide to replace the fuel pump, electric conversion will be more expensive than replacing the mechanical.

 

[Tim71FJ40]

But which will work better? I've got so much money is this project, if the only thing between me and driving is an electric fuel pump, I'm willing to pay for it.

Do you have a clue why my old one wouldn't work? It worked when we tore the truck down 2 years ago.

 

[CruisenSurfin]

I have seen situations where the check valves (there are two) have frozen due to varnish. To resolve this issue I have blown air (at low pressure) from the supply side of the pump forcing the valves to unstick.

Other issues could be you are not waiting long enough for the pump to prime itself or the float in the carb could be stuck. How long did you crank the engine? Has the carb been cleaned?

Don't go with an electric fuel pump. It is more trouble than fixing the real issue.

 

[Tim71FJ40]

It turned over several times but would only run a couple seconds with the small amount of gas we poured in carb. Probably turned it over 6 or 7 times. It didnt even pull fuel one foot into the filter. The carb is brand new.

 

[CruisenSurfin]

You could also try pouring fuel into the supply line and filling up the filter first. But I still think the check valves are stuck. Try blowing air through the line before buying any new parts.

 

[Tim71FJ40]

Blow thru it from the fuel tank side, not the carb side?

Thanks

 

[CruisenSurfin]

Right, the check valves only permit fuel from flowing from the tank to the carb. So you must blow air in the same direction.

 

[CruisenSurfin]

In-fact you should not be able to blow air (very low pressure) from the carb side to the tank. If you can that means the check valves are stuck open. If they are stuck open (even one) than the fuel pump will not be able to create a vacuum thus not be able to draw fuel from the tank.

 

[Tim71FJ40]

Since it's actuated mechanically by a lobe of the cam, is it even possible that the wrong cam was installed when the engine was overhauled?

 

[Pighead]

No. If your engine runs, it's the right cam. Try putting your fuel supply above the fuel pump and see what happens.

 

[3_puppies]

let me make sure I got this correct, you are using an earlier fuel pump, 2 hoses, instead of the 79 pump which has 3 hoses?

any chance you left the spacer from the 3 hose pump on the block? the 2 hose pump does not use a spacer and has a shorter arm that will not hit the cam lobe if the spacer is there.

 

[Tim71FJ40]

Two hoses, no spacer. But I'm pretty sure I remember blowing slowly through the carb side and feeling it at the gas tank end. Per the post above the check valves should prevent that. Maybe they're stuck open.

On the three hose version, what is the third hose for? There's a supply from the tank, one to the carb, and the third goes where???

 

[Tim71FJ40]

Because I also have a new 3 hose pump, but when it didn't look like the old one I put it back in the box and onto a shelf...

 

[LAMBCRUSHER]

third pipe is the fuel return line. the later models had the return at the pump rather than the carb.....I like the late model pump more...it cuts one more fuel line out of the mess of stuss on top of the motor.....

 

[Shark56]

ALL-FOREIGN CAR PARTS - Import & Domestic Car Parts, Import & Domestic Truck Parts, Brakes, Rotors, Distrubutors Fuel Pump&mode=PA

I would put a new O.E.M. in after spending the bucks for a rebuild.

 

[Shark56]

You can also block off the return line on you new pump.

 

[Pulso]

You need a longer test of the pump than just a few seconds of the engine running. Keep the gas can on the floor with a hose that the pump can draw from. Get another gas can, place it somewhere higher than the carb, with a hose going to the fuel intake on the carb. Take the fuel line from the pump and feed it into the gas can that is supplying the carb. See what happens.
When I replaced my pump recently it took awhile to get things flowing.

 

[mydogpea]

ALL-FOREIGN CAR PARTS - Import & Domestic Car Parts, Import & Domestic Truck Parts, Brakes, Rotors, Distrubutors Fuel Pump&mode=PA

I would put a new O.E.M. in after spending the bucks for a rebuild.

X2! Old parts on a newly rebuilt engine...