Fuel pump problems

[steve5]

Any thoughts on where I go next?
Dolly 1500HL, suddenly stopped with fuel starvation. Nothing coming out the pump so I assumed it had failed. Just fitted a new one, still the same. Connected the old one to the tank feed line and pumped by hand, fuel comes through OK. Put the old pump back on, no joy. Certain it is fitted correctly. The camshaft does not seem to have snapped as I can see the pump drive cam moving. If I pump some fuel into the float chambers the car starts first time and sounds fine. At a loss now, apart from going electric.

[geeksteve]

It's a bit of a faff to get the pump on right. it's possible to get the cam the wrong side of the arm.

S

[steve5]

I know that can be done, but of i loosen the nuts and turn the engine by hand I can see the pump body being forced down which means the arm is being lifted up. I am thinking that the new pump must be a dud.

[geeksteve]

Is there a spacer? Not sure if it applies to all models but i've seen talk of having to add/remove spacers depending on the pump / arm shape. Always turn engine over by hand if you change that though, you don't want to ruin it. If it pumps by hand I can't see how the pump is duff.

Steve

[Howard81]

Have you checked the fuel line back to the tank? I had partial blockage in the tank cause similar symptoms..

[WDRVM]

Have you checked the fuel line back to the tank? I had partial blockage in the tank cause similar symptoms..

+1. Definitely worth checking the tank. I had a considerable amount of rusty crust blocking the fuel line outlet in the tank, seemingly fuel starvation at the pump. Syphoned the petrol out of the tank through some muslin (to catch the crud) via the float valve hole, removed the crud, refilled the tank and changed the fuel filter(to be sure) and no problems after that. You do need some fairly wide bore hose (half an inch or so i/d) though to "Hoover" up the rusty crust. You can often see the crust build-up by the fuel outlet in the tank by looking through the float valve entrance hole.
Best of luck.

[steve5]

Guess the fuel line is next , I'll have a go later on and see what I can find.

[Jon Tilson]

I suspect that one of your rubber joining sections has a small pin hole allowing the pumps to suck air.

Test both pumps and see if they will pull fuel up from a can through a known good short length of pipe.

If they do, you know where to look.

Its quite hard to get the pump on the wrong side of the cam on an ohv car. In fact I dont think I have ever done it.
It is however quite easy on a slant.

Jonners

[DaltonBarham]

I'm having almost the same issue-
don't think its pin prick holes as this all the rubber sections are new as is the pump.
Might be a blockage though- i'll try and have a look tommorow

[Jon Tilson]

The likely blockage point is the tank union pipe. Be prepared to catch the entire tank contents in the boot floor if you undo it in situ...
The tank comes out pretty easilly so I'd always recommend this if you want to take out the tank union.

Jonners

[steve5]

When it first happened I assumed it was a blockage in the tank outlet , but when I popped off the outlet hose underneath I got a nice gush of fuel, there was some crap in the pump filter though so it may be a part blocked pipe somewhere. And regarding fitting the pump wrong, I have done many of these and I am not sure how you can fit them wrong, maybe different on the slants, and in my case it would not explain the original problem. I have a roll of fuel pipe which I am going to run from the tank to the pump to see if it is a blockage causing it. Hopefully tonight I'll find out..

[steve5]

Sit-Rep, ran new fuel line from the tank to the (new) pump, nada.
Hung the old pump on the hose and after a couple of pumps by hand I had a nice flow of fuel.
Put hose back on the new pump and it started first time, running fine ever since.
So the old pump was OK, must of been either a blockage or air leak somewhere.
The big question now is, is it legal?, the hose I used is the thick black reinforced rubber stuff, I have cable tied it following the original pipework run, so I see no safety difference to the original metal/platic hose mix.

[Ron1966]

Check the steel pipe over the axle Steve. Had a problem similar to yours with starvation and the pipe over the axle had a small hole and corrosion where it fitted into the plastic securing clip. Because this is higher than the tank mine showed no sign of a leak but must of been sucking air and not much fuel.