Fitting an electric fuel pump

[Quart Meg Miles]

I have now detached and plugged the tubing after the regulator and the pumping noise continues. When the plug is released briefly the noise deepens as the petrol flows. I'm now sure there is no air getting in on the inlet side.

Is this how a Facet Posiflow is supposed to work? That is, it always pulses? I've emailed my supplier, assuming it's a faulty unit, and will post their response.

Meg

[billwill]

I don't have a Facit. Not sure what brand mine is unless I check pictures against a supplier, but mine reduces the rate of clicks to near zero if the engine is not running.

I presume it is controlled by back pressure in the output fuel line, so perhaps yours has a faulty sensor.

[types26/36]

Is this how a Facet Posiflow is supposed to work? That is, it always pulses? I've emailed my supplier, assuming it's a faulty unit, and will post their response.Meg

I have a Facet connected in my fuel supply (although I only switch it on when the car has not been used in a while) its just for priming the carbs as the trusty old glass bowled pump works fine.
Initially it is quite loud until the carbs are full then carries on rattling away like a machine gun but not as loud and it does not stop until I switch it off, I thought this was normal for a Facet so will be interested to see what response you get from the supplier.

[Quart Meg Miles]

Thank you Bill, what you describe is what I anticipated;

Thank you Brian, that's what is happening and is confirmed as correct by Demon Tweeks.

The "electronic" part just seems to be a timer pulsing a solenoid coil which tries to reset the pump plunger against its fuel-forcing spring. If there's no flow the plunger can't move so just thumps but if it is fully or partly down its cylinder it moves an appropriate amount and thuds more loudly against the end. It's inaudible when the engine is running or switching on in a street and the extra amps shouldn't be a problem.

With the regulator where it is I don't suppose I can switch the pump off, Brian style, but I'll see what happens. I have designed a two-relay-plus-transistor oil pressure switch cut-out with automatic start but I'll only build it if the pump is permanent.

Thanks agaian, guys.

[Pistacchio sprint 72]

Hello,
How can you tell a m?ch pump is leaking fuel into the sump diluting the engine oil?

[nomad]

I've experienced the leakage and, as I remember, the engine oil will smell of gasoline. Also an overfilled sump or sump that gain's slightly gives a good idea.

Kurt
26/3754

[alexblack13]

Hi Guys / Meg ...

The little rubber resiliant mounts I had in my box o bits. I think they were for exhaust mount possibly? Not sure. but one can also buy them from Ebay or online from various suppliers..

let me know if you cant find and i will Google around and find them for you.

BTW My little posiflow does not stop entirely either. esp set at just 1.5 Lb / 2" ... i think either thr reg diaphram or the elasticity in the upflow pipery... I have left it running (the pump) for ages and no flooding at all so now I just dont think about it. Def' no leaks. Works a treat.. I really have to listen for it it is so quiet.

Been away guys (now retired and have new motorhome will travel)....

Take care now..

[Quart Meg Miles]

Thanks, Alex,

I'll stick with my rubber grommets as I can barely hear the pump running in practice and not at all with the engine running. Your mounts look a bit smaller than the exhaust bits they sell in southern England.

While working in the empty boot I thought I could smell petrol (it's probably seapage from the filler just above) so while I de-rusted the top of the fuel tank I left the pump running so I could check for leaks. After perhaps ten minutes there was a metallic racket from the pump as if it was shaking itself to pieces so I quickly switched it off. Without petrol flowing I believe it had locally vapourised the petrol, by cavitation and heating, and was working in vapour so had no damping as it hit the end stops. When I started the car next day it was normal so either the vapour had condensed or been pushed through as the Webers evaporated petrol.

The tank is now coated with Galvafroid which was a wonderful cold galvanising paint I bought decades ago and hope is still available. It has lasted at least twenty years on an outdoor pressed-steel item on the house where the original galvanised finish had rusted through. Now that St Wilkins only powder-coats his chassis it might be a useful accessory. Oops, rather off topic.

EDIT While looking to replace the tin of Galvafroid I discovered Zinga (www.zinga-uk.com) which appears to be a superior product and I'm getting a tin today. Can overcoat Galvafroid and I will post observations.

[l10tus]

Reading through these answers I noticed that nobody mentioned the upgrade of the fuel supply pipe is required when converting to electric "pusher" Facet type pump?

The original glass bowl pump is capable of sucking petrol from the tank, then supplying fuel to the carbs via. a short length of reinforced pipe.

But when using an electric pump mounted by the tank, the small Nylon fuel tube, running in the chassis spine to the carbs is under now under pressure, so the push fit rubber pipe joiners become rather suspect ,in use maybe?

Has anyone who converted to rear mounted electric Facet type pump, but retained the original black nylon tube, ever had any issues with the now pressurised system, leaking?

I used solid pipe with mechanical olive clamping nuts to ensure no possible leaks, on my installation.
RSVP?
Cheers,
Phil.

[Phil.C60]

I used the Edelbrock pump from Webcon (https://www.webcon.co.uk/products/48-12 ... 20-35-psi/), 2-3.5 psi mounted in the boot between the diff mounts. Has it's own pre-filter and I did fit a lastic filter between the pump and the fuel line to the front. I was a little concerned that the fitting instructions suggested that it needed to be gravity fed, but after a conversation with the technical guy at Webcon who assured me that the small amount of lift from the tank would not be an issue I went ahead and it's been fine for over a year and a couple of thousand miles. Easy and neat to install, not too noisy and no regulator or return line required. I didn't want any more clutter in the engine bay than absolutely necessary. I mounted it by drilling two holes in the floor and cable tying it with a rubber pad underneath. The ideal is with an inertia switch, I have one from a Triumph Stag but that's still in my parts box! Works for me....

[RichardHawkins]

Phil,

Where are these push fit rubber joiners? My car (S4 coupe) has a nylon tube inside the chassis with a compression fitting at the pump in the boot and another compression fitting in the engine bay where the mechanical fuel pump used to be.

Hope this helps,

Richard Hawkins

[l10tus]

Richard,

Thanks for the reply.

The nylon black (OEM) pipe runs thru' the backbone chassis, via a grommeted hole through the fibreglass body, into the open boot area. The nylon pipe was originally joined to the metal 5/16 " diameter feed pipe from the petrol tank, with a push-fit rubber pipe, on my Sprint there were no clips at all.

I believe this was the normal jointing method from the factory, as the fuel pump "sucked" fuel from the tank - unlike modifications using a facet type electric pump that now pressurised the line ( causing possible leaks?).

[Elanman99]

I can confirm the description of the fuel pipe run and connections given by Philip was indeed how the cars left the factory. I have seen the same from the S1 onwards.

I no longer have an original steel tank but I'm sure that on my S4 the outlet stub was 1/4" diameter not 5/16"

In about 1970 I fitted a Facet pump (in the boot) and its been running ever since

Ian

[RichardHawkins]

Thanks for the replies, sounds like my S4 has been altered by a previous owner.

Richard Hawkins

[Phil.C60]

I got a bit confused as there are now to "Phils" posting! On the +2 I did some work on a few years ago, the outlet from the tank was a compression fitting. Om my S4/Sprint it was a push on fitting at the tank, and originally compression fittings at the fuel pump. The tank connections were straightforward to the Edelbrock pump, as it's still under vacuum at that point and from the pump to the original nylon line was secured with good quality clips and the correct size fuel hose that only just fitted over the nylon pipe using Vaseline. At the pump end, the nylon line had previously been repaired/joined with some dodgy fuel hose, probably when someone replaced the original glass bowl pump with a metal one with push on ends which was knackered. I replaced the dodgy fuel hose as per the rear, and used a compression fitting type braided y-hose set from Kelvedon so the stub on that fitted inside the new fuel hose. Two decent clips and Bob was my avuncular relative. It's been fine ever since. I was originally concerned about the fact that the nylon pipe is now pressurised, which it was not designed to be, but it's been OK up to now.....