Fuel pump issue

[Wookie 66]

Hello all

The sarga continues I have a new fuel tank new fuel lines kits through the original glass fuel pump and standard carby.

Is there any special way to put the fuel pump together ?

When I’m turning the engine over I can see the fuel in the glass bowl it appears to be pumping in, it seems to only pump out a dribble into to carby the lines are clean and clear.
When the engine fires and runs for a few seconds does a bit of coughing and a back fire and stops its like the pump can’t  pump enough fuel to the carby to keep the fuel for it to run

The carby is also leaking fuel from shaft area under the fuel reservoir I’m guessing warn and can’t be fixed with a kit?

Any direction would be appreciated

Thanks

[mcl1959]

Has the braided flexible line been replaced, this is a common source of fuel supply problems
Ken

[Wookie 66]

Hi Ken

Yes the Flexi hose is new
I had a good play today and got the issue down to once the fuel is out of the carby reservoir it its not pumping in but if I take the line off it pumps the fuel no probs

[ardiesse]

Fuel leaking out around the throttle shaft just means you've been pumping the throttle too much with the engine stopped.  For the moment this isn't a problem.

Best thing to do is take the top off the carburettor: undo the choke cable inner, then remove six screws.  Be careful not to drop anything down the guts, and make sure the gasket stays on the carburettor's main body.  When you've lifted the top clear, turn it half a turn so it's upside-down with the front facing the firewall, then you can disconnect the choke rod and put the top down in a safe place.

The fuel level should be 16 mm below the top face of the main body.  If there's no fuel in the bowl, the needle and seat are either blocked or stuck.  Unscrew the fuel pipe from the inlet, then undo the brass fitting.  The needle should fall out in your hand.  Blow through the fitting to make sure it's clear.

Put the needle and seat back in, reconnect the fuel pipe, pull the HT lead out of the coil, and crank the motor over.  The fuel bowl should fill to the right level.  To check that you've got static fuel pressure, push down on the top of the float briefly, and you should see fuel rush into the bowl.

If the float level's right and fuel runs in when you push the float down, the engine should start.  Put the carby back together, reconnect the HT lead and see whether it goes.

Coughing and backfiring are symptoms of lean mixture.  If the engine still coughs and dies, then you may have blocked jets.

Is your ignition system in good order?

Rob

[Wookie 66]

Thanks Rob
I’ll have another look at this area today
I’ve re wired the car it’s all brand new as per the factory wiring diagram new ignition
Thanks for the info

[Wookie 66]

Hi Ken what’s the issues with the braided fuel lines?
It’s brand new only thing I could see is the hose might get pinched to much
If it is what’s an alternative another new one ?

I’ll check this possibility out as well

[Wookie 66]

Ok double checked everything carby is clean no blockages
The braided line is good all the other lines are clean and clear
I’ve concluded the pump itself is crap can’t get the fuel to pump to the carby

I’m going to ditch the glass bowel and get a new pump without the glass
That or go an electric pump
Engine runs fine now until the carby is empty obviously no fuel no go

Cheers

[ardiesse]

Trevor,

Take the pump off.  Operate the rocker by hand.  The pump should sound a bit like a frog as the valves do their work.  If you can hear a croak as you move the rocker both in and out, the valves are OK.  If you don't mind risking petrol-mouth, here's how to to test the valves in the fuel pump -
Put the "IN" fitting up to your lips and blow.  It should flow, with some resistance.  If you suck, there should be no leakage.  Now put the "Out" fitting to your lips and suck.  It should flow.  If you blow, there should be no leakage.

While the pump's out, attach a tube to the inlet and put the other end of the tube in a can of petrol.  Operate the rocker by hand.  The pump should fill, and petrol should flow out of the outlet.

The only other cause of no-flow is a broken link or diaphragm pull rod.

Rob

[MalFE]

Can you pressurise tank to see a good flow of fuel passing through line and do you have a vented fuel cap.

Mal.

[Wookie 66]

Hi Mal

How do I pressurise the tank?

Standard twist on of cap but I though of that so I took it off made no difference

[Errol62]

You can blow  compressed air back through the fuel line make sure it is clear.

Sent from my SM-G973F using Tapatalk

[my8thholden]

wrap some cloth around your air blow off gun and seal it as best you can in fuel filler to tank and pressurise tank and catch fuel at other end ,it doesnt need a lot of pressure,Vern .

[Wookie 66]

Hmm put on what came off just new stuff don’t recall seeing a fuel filter
I guess I’ll have to put one on and cut into my new fuel line.

Thanks for the info I’ll have another go at getting it to work
Cheers

[mcl1959]

There was no fuel filter originally, it’s better to have one of course, but I wouldn’t put one in if you are looking for originality

Ken

[Wookie 66]

Hi all
Can anyone advise on how much pressure the glass bowl fuel pump produces
For example if I disconnect the carby fuel pipe and hold my thumb over it for a seal and crank the engine should there be pressure to force the fuel past my thumb to spurt out?

Cheers

[Dr_Terry]

Hi all
Can anyone advise on how much pressure the glass bowl fuel pump produces
For example if I disconnect the carby fuel pipe and hold my thumb over it for a seal and crank the engine should there be pressure to force the fuel past my thumb to spurt out?

Cheers

I believe the factory spec is 3 to 4 PSI.

Dr Terry

[Wookie 66]

Thank to those who provided info and advice on this subject
Just to Finnish the issue I don’t know what was wrong with the glass bowel pump as it seemed to work for what every reason it just would not fill the carby

Put on a new after market fuel pump primed the carby and turned the key the old girl lives again she’s running great

Cheers