do i need a 6v or 12v fuel pump?

[LoveB]

question time, I've plugged my 12v fuel pump (which was on the vehicle when it ran in october) directly to the battery to see if that made a difference but it appears its not sucking enough fuel up the line to get the car running again? it did before but when I revved it it would miss....

ive got a 12v pump and someone told me to use a 6v as it takes less power to get it going? (is the S1 even 12v?) I'm gonna get a fuel pump tomorrow but i just need to know what kind..

[Aaron IIA]

Series I Land Rovers are 12 volt positive earth. If it has had an alternator fitted, it will most likely now be negative earth.
Aaron.

[Aaron IIA]

Are you still using the original SU fuel pump? Have you cleaned the valves and set the points?
Aaron.

[Blknight.aus]

which 12v pump are you using if its one of the original ones if you dont set them up just right they are a slug..

count the cells on your battery if you have 6 cells you need a 12v pump. any facet pump will do but if you want to maintain the OEM one it will need servicing.

[LoveB]

Still original (well replica, its branded harting)

it was last working in november. had the same issue prior but it managed to suck fuel up and get it running then. it was opened up and cleaned and put back together. now it doesnt seem to suck eonugh up. Maybe the glass? I need to check the hoses tomorrow. I put more fuel in the tank to make sure there was fuel to suck up anyway. and I'll give it another shot.

still positive earth on this one. I've still got the original generator on it. i tried another aftermarket fuel pump (which was much much younger) and that didnt even work at all! lol

[Blknight.aus]

some of the newer facet style pumps are solid state and wont work on positive earth.

the ones with 2 wires coming out of the electrical grommet dont care which side is earth as the body is electrically isolated

the early pumps didnt care which way the voltage was applied but some had a diode in them or a capacitor which was ment to arrest voltage spikes when the pump was "returning" after completing a stroke, the diode version got hot until the diode blew out and would then work IF the winding hadnt given out first.

[LoveB]

i might just try and plug it to the battery again tomorrow and see if i leave it for 30 secs or so if it would suck up enough petrol. hope so. its just easier to move it around when its running. i need the carby rebushed as its got a bit of a leak coming from the shaft. lol

[LoveB]

ive got two pumps branded harting as per my s1 thread. im really keen to get it going so once i can move it around the workshop i can then work on the brakes and what not. but the other pump doesnt go at all. if all else fails i will pickup a cheap 12v pump from supercrap tomorrow and plug it straight into the battery for when i need to start it

[Blknight.aus]

or just get a small fuel can, braze a barb onto it and set yourself up for a gravity feed fuel system.
you can also do the same with a boat fuel tank or the fuel tank off of a lawn mower.

[Hartley]

Modern pumps often deliver with too much pressure and push past the float valve and cause flooding

[101RRS]

Modern pumps often deliver with too much pressure and push past the float valve and cause flooding

Not if you get the right one - you can get them down to 1 1/2 psi.

Sorting the original fuel pump can take time and take you away from other tasks. If it were me I would but a low pressure electric on from Ebay - about $30 so the engine will run and come back to the original pump when the vehicle gets on the road - then keep the newer pump as a spare.

Garry

[drifter]

When we last got Ricks Series 1 going the pump needed a helping hand/mouth. Basically, it needed priming. Once primed it ran very well. We were the supervisors. We let Rick suck the first load!

[LoveB]

how do i prime it? just suck it up??? lol

[drifter]

That's what we (he) did. Disconnect the pipe from the tank at the pump end and loosen the pipe at the carby. Get the pump running. Suck until there is fuel at the top of the pipe. Quickly attach it to the working pump and, hopefully see a squirt of fuel at the carb.

[Blknight.aus]

do it the easy way, stuff a rag with a air duster in it into the filler cap and gently preessurise the tank

[drifter]

Where's the fun in that?

[digger]

Not if you get the right one - you can get them down to 1 1/2 psi.

Sorting the original fuel pump can take time and take you away from other tasks. If it were me I would but a low pressure electric on from Ebay - about $30 so the engine will run and come back to the original pump when the vehicle gets on the road - then keep the newer pump as a spare.

Garry

so what sort of PSI should we be looking at??

cheers

[Blknight.aus]

~4psi

[digger]

~4psi

Cheers Dave,

forgive my ignorance (and I have lots of it!) I thought that these pumps usually were meant to be installed at lower than the sitting fuel level...

is that the case, if so where is a good spot to mount on an 80" that wont get wiped out?

[101RRS]

so what sort of PSI should we be looking at??

cheers

I have no idea what PSI the Series 1 32 Solex runs at but you can get the cheap electronic pumps at varying flow rates and varying pressures.

The one I have on my Haflinger runs at 1.5-2 psi. It ran a 34 Solex I had on it OK and the current twin throat Zenith quite well.

Garry

[russellrovers]

Cheers Dave,

forgive my ignorance (and I have lots of it!) I thought that these pumps usually were meant to be installed at lower than the sitting fuel level...

is that the case, if so where is a good spot to mount on an 80" that wont get wiped out?
hi dave they are designed to pull at 4psi you can set a spare push pump next to the tank it also pushes through the su regards jim

[zulu Delta 534]

Before going off at the fuel pump I would be tempted to ascertain what condition the fuel pipes between the pump and the tank are in. Are ther clogged? Is the gauze on the end of the pick up in the tank still in position and unclogged? Are all the joints still dry? a wet joint will show that the pump may be sucking a small amount of air as well as petrol and as a result not delivering enough fuel.
Once all these points have been checked - perhaps you could even try manually sucking fuel through the pipe system- then and only then would I be looking at the pump.
A blockage after the pump between the pump and the carburettor could possibly have the same effect of limiting fuel flow.
If this is the first time the vehicle has run since October I would also be suspicious of the condition of any fuel that has been left lying around in the system. Modern day fuel, if left for a long period of time will evaporate and leave a shellac like substance in its place which is often enough to restrict any future flow through the affected area.
In answer to the original question, the answer is 12 volt but take into account the polarity of the battery when ordering, as a positive earth pump will not function on a negative earth system, nor vice versa.
Regards
Glen

[LoveB]

used our primer at work. got it to prime and put it on. it ran fine. was idling fine withuot me in it.

but after a while it died. lol i think the fuel pump goes cactus once its warms up. the pump felt warm too. i should proably just try and rebuild it and get a low pressure pump on ebay.

[Blknight.aus]

Cheers Dave,

forgive my ignorance (and I have lots of it!) I thought that these pumps usually were meant to be installed at lower than the sitting fuel level...

is that the case, if so where is a good spot to mount on an 80" that wont get wiped out?

in an ideal world yes because it means the essentially self prime if you get a vapour lock or run out of fuel.. (well they dont have to work so hard anyway

the pumps are better at the push side than the draw side.