Series 3 Red top pattern fuel pump pressure

Hello
I was wondering what pressure reading my patten red top electric fuel pump should be providing, how I could measure it and whether it can be regulated.
It’s pushing fuel out of the over flow pipes on my twin SU’s and I know it’s not the floats/float settings or needle valves.

Any ideas?

Thanks a lot Paul.

Which engine? Is it a stage 1?

Wildefalcon said:

Which engine? Is it a stage 1?

Click to expand...

It's a 3.5 v8 (out of an early range rover).

Photos of pump? Not familiar with red top pumps. Do you use a swirl pot or tank? I suspect you might have a EFI pump. Get the standard RRC pump and see what happens.

Do you have pics of the setup.
Some have a return line back to tank so as not to overpressure the float chambers if i remember. Are you sure its the overflow and not the return?

You have just had your carbs redone, haven't you?

J

Standard pumps are mormally 6psi. Good enough for v8. If you have a rubber pipe near the pump just squash/restrict with grips & pump should stop.

Photos of pump may help.

And I think your problem is float height settings.
How are the tips of the float needles? These are a rubber & can get a ring in them

Wildefalcon said:

Which engine? Is it a stage 1?

Click to expand...

It's a 3.5 v8 (out of an early range rover).

Hicap phill said:

Standard pumps are mormally 6psi. Good enough for v8. If you have a rubber pipe near the pump just squash/restrict with grips & pump should stop.

Photos of pump may help.

And I think your problem is float height settings.
How are the tips of the float needles? These are a rubber & can get a ring in them

Click to expand...

Floats, float heights and needle valves all spot on. Will check all the pump stuff when I get home from work. Thanks vey much everyone.

marjon said:

Do you have pics of the setup.
Some have a return line back to tank so as not to overpressure the float chambers if i remember. Are you sure its the overflow and not the return?

You have just had your carbs redone, haven't you?

J

Click to expand...

Hi yes. Well remembered! They came back from Burlen and it's fixed a weird runnin g issue I had. They had these weird over run valves fitted which have now been ditched. Flats, needle valves, seals all replaced. Definitely coming from the overflows as I have a fuel return pipe going back to the tank.

Floats not flats!

Photos of pump to follow when I next get a chance ti have a tinker.

NowayPedro said:

Hi yes. Well remembered! They came back from Burlen and it's fixed a weird runnin g issue I had. They had these weird over run valves fitted which have now been ditched. Flats, needle valves, seals all replaced. Definitely coming from the overflows as I have a fuel return pipe going back to the tank.

Click to expand...

I guess checking the return line is clear would be a good place to start then.

Believe there a restriction somewhere too.

J

marjon said:

I guess checking the return line is clear would be a good place to start then.

Believe there a restriction somewhere too.

J

Click to expand...

Few thoughts… (up to early for the brain cell to be working fully)

the floats should stop any fuel through the over flow?

If the pump is an interrupter type it should stop pumping or slow down once carbs are full.

Hmmm…..not sure about that. As there would be no point having factory fitted overflow ports and drain pipes from the carbs.

NowayPedro said:

Hmmm…..not sure about that. As there would be no point having factory fitted overflow ports and drain pipes from the carbs.

Click to expand...

If the floats are not set right or stick they will over flow. Some time as tap with the end of a screwdriver handle would sort it.

Where else so you think the fuel could be coming from?
Been about 30years since last looked at SU carbs in anger

Thinking the return to tank pipe could be blocked as suggested further up the thread. Will investigate. Floats and all associated parts are spot on.

Well thank you so much everyone. There was a bloody great screw inserted into the fuel return pipe when I removed the pipe from the petrol tank! Removed it and put the pipe back on. I ran for 20 mins and no overflow!!! 'm ecstatic!!

Got to love previous owners .

J

Hilarious. Such a weight off though I can't tell you. I'm going to the pub!

The question is what devilry was the PO trying to cure when he stuck the screw there in the 1st place?
Now it’s gone, 3 months down the road you’ll no doubt figure out what the bodge was trying to sort - just after you’ve forgotten you removed it
Good sort tho.

I'm thinking a tank removal happened at some point and it was a plug. But would have been fairly hard to miss when it went back together. That said it was screwed in a long way.