Electric fuel pump

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Re: Electric fuel pump

Post by Peter-S »

pbar wrote: Sun Sep 25, 2022 8:29 pm
Mr B wrote: Sun Sep 25, 2022 7:30 pm The car of mine that has this issue would quite happily drain and flatten battery after battery if I let it

That is a definite problem your car has, obviously. It should only take a few seconds of cranking for the fuel to be delivered and the car to spring into action. After you have done a ton of cranking as you describe (and perhaps a flat battery), do you actually have any fuel in the carb? If you do then the issue is elsewhere. If you don't then fuel isn't being delivered.
I get similar on the 2.0. It's fine when used fairly regularly but parked for longer periods and it needs some assistance. Don't know if it makes a difference but it is running a 38dgas which I assume is what MrB would be using whilst Pbar is presumably on a 32/36.
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Re: Electric fuel pump

Post by [email protected] »

So what we seem to be saying is just about everyone has the issue (If they don’t have an electric fuel pump) but have issued a collective “meh” and shrug of the shoulders? :xd: It’s just something that never happened (a decade and more ago) when I drove it regularly and now it’s back on the road seems to happen every time I leave it stood for a couple of weeks. Once it returns from its pamper session, mani pedi and facial (respray attempt no 2) I will look into the matter. Easy starting after weeks has it’s appeal
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Re: Electric fuel pump

Post by Mr B »

pbar wrote: Sun Sep 25, 2022 8:29 pm
Mr B wrote: Sun Sep 25, 2022 7:30 pm The car of mine that has this issue would quite happily drain and flatten battery after battery if I let it

That is a definite problem your car has, obviously. It should only take a few seconds of cranking for the fuel to be delivered and the car to spring into action. After you have done a ton of cranking as you describe (and perhaps a flat battery), do you actually have any fuel in the carb? If you do then the issue is elsewhere. If you don't then fuel isn't being delivered.
No fuel in the carb what so ever, I have an in-line fuel filter between the pump and the carb and nowt in there either, I guess the fuel is evaporating which, as someone has already pointed out, is hardly surprising as the carb on an Essex V6 is literally being cooked on top of the engine, but why the pump refuses to feed the carbs appetite after a couple of weeks of no starting remains a mystery...
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Re: Electric fuel pump

Post by pbar »

Thanks for your reply Wayne. My carb will be empty also after 2 or 3 weeks or so, that's quite normal, it evaporates. However, after a few seconds of cranking the fuel makes its way to the carb (can be seen in the inline filter as you mention) and the car will start. Takes a little longer as I've said, than when the car is frequently run, but it hasn't been an issue, and that's always been the case in ten years or so. Now, your car isn't doing that obviously, carb remains dry so it will never start. Can only think you have a blockage of some sort or a faulty pump, faults which are evident at startup but clear during normal running. After the car has been left for a while, put a hose from the pump into a container, see if fuel is actually even being pumped during cranking or not. Sounds like it isn't.
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Re: Electric fuel pump

Post by Mr B »

pbar wrote: Mon Sep 26, 2022 8:11 pm Thanks for your reply Wayne. My carb will be empty also after 2 or 3 weeks or so, that's quite normal, it evaporates. However, after a few seconds of cranking the fuel makes its way to the carb (can be seen in the inline filter as you mention) and the car will start. Takes a little longer as I've said, than when the car is frequently run, but it hasn't been an issue, and that's always been the case in ten years or so. Now, your car isn't doing that obviously, carb remains dry so it will never start. Can only think you have a blockage of some sort or a faulty pump, faults which are evident at startup but clear during normal running. After the car has been left for a while, put a hose from the pump into a container, see if fuel is actually even being pumped during cranking or not. Sounds like it isn't.
See that's the bit I don't understand, if used every day or even every other day she is absolutely fine and starts on the button and the car performs exactly as it should out on the road, yet leave it a couple of weeks and it's a no start every single time without fail - all with the same fuel pump which is the bit that doesn't make any sense to me.

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Re: Electric fuel pump

Post by pbar »

Wayne, it is easy to understand, when used frequently the fuel remains in the carb, it doesn't have time to evaporate. But, when left it does evaporate, and when this happens the fuel pump needs to replenish the carb with fuel when cranking. But that process is failing on your car. Try the experiment I mentioned and see what happens.
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Re: Electric fuel pump

Post by SCP440 »

pbar wrote: Tue Sep 27, 2022 12:00 am Wayne, it is easy to understand, when used frequently the fuel remains in the carb, it doesn't have time to evaporate. But, when left it does evaporate, and when this happens the fuel pump needs to replenish the carb with fuel when cranking. But that process is failing on your car. Try the experiment I mentioned and see what happens.
Yes exactly, put 100ml of petrol in an open container somewhere safe, it will all be gone in a couple of weeks if not sooner. The carb on our cars has numerous air passages so it will evaporate the same. Also when you switch off the heat in the engine bay will probably make some evaporate a lot quicker. Modern fuel is different to the stuff produced 40 years ago, a lower evaporation point and different additives.
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Re: Electric fuel pump

Post by Mr B »

SCP440 wrote: Tue Sep 27, 2022 7:44 am
pbar wrote: Tue Sep 27, 2022 12:00 am Wayne, it is easy to understand, when used frequently the fuel remains in the carb, it doesn't have time to evaporate. But, when left it does evaporate, and when this happens the fuel pump needs to replenish the carb with fuel when cranking. But that process is failing on your car. Try the experiment I mentioned and see what happens.
Yes exactly, put 100ml of petrol in an open container somewhere safe, it will all be gone in a couple of weeks if not sooner. The carb on our cars has numerous air passages so it will evaporate the same. Also when you switch off the heat in the engine bay will probably make some evaporate a lot quicker. Modern fuel is different to the stuff produced 40 years ago, a lower evaporation point and different additives.
Morning gents,

I totally get the petrol evaporates after a few weeks, the point I'm trying to make is how can the fuel pump replenish a carb that is say a quarter to half full (every day use) but cannot replenish a carb that is empty after a couple of weeks?

What changes between a carburettor bowl that's empty and one that's half full, the fuel pump should still do it's job, right?

I have tried pbars suggestion of pulling the pipe when it happens and putting it in a jar and no fuel is being pumped out at cranking speed, repeat the test when the pump has been in use within the last of couple of days and it'll drown you in petrol!

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Re: Electric fuel pump

Post by pbar »

Hi Wayne, probably best to try another fuel pump, it is possible that yours is under performing and/or faulty. Either way it definitely needs ruling out.
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Re: Electric fuel pump

Post by Mr B »

pbar wrote: Tue Sep 27, 2022 9:27 am Hi Wayne, probably best to try another fuel pump, it is possible that yours is under performing and/or faulty. Either way it definitely needs ruling out.
Perhaps when the fuel evaporates in the pump if effects the internals of the pump in some way, but I agree with you mate, tbh I should have changed it ages ago but all my efforts have been focused on my daily driver and trust me she'd keep anyone busy! :lol:

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Re: Electric fuel pump

Post by pbar »

It's difficult to explain why things behave a certain way due to faults, just look at electrical gremlins, can be a nightmare. Could be that when the system is dry, carb, hoses and pump all dry, that the pump is failing under the extra strain as it is past its best but can still perform under easier conditions. I'd also check things like the fuel tank breather, make sure nothing is astray which may make the pump struggle, like there's extra pressure or a vacuum or something. I'd definitely try another pump and see how that performs I think.
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Re: Electric fuel pump

Post by SCP440 »

A fuel pump is designed to pump a liquid, when it is dry you are asking it to pump air, yes it will pull a vacuum but if it is underperforming is will struggle.
Do you have a fuel filter before the pump? Could this be partially blocked? A tiny hole in the pipe could go unnoticed as far as a fuel leak but if it is before the pump it will suck air before it will pump fuel.
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Re: Electric fuel pump

Post by Mc Tool »

Yeah Wayne , Im thinkin pbar might be right in that if your pump is a bit suss and not priming well.
I pulled one apart and it had steel reed valves and seats .....which is all well and good if the surfaces are in good cond ( these were but the pump was leaking oil ).
And scp440 has a good point too about the filter placement ,any restriction on the suction side isnt going to help .
I would have thought the valves and /or seats would have some rubber-ish material in there.
I guess there isnt much you can do about fuel evaporating but leaking pump seals leaves you with.....
Fuel evaporating
Leaky valve in pump allowing drainback
and the same leaky valve causing priming issues.
Ha ha yeah , stick an electric pump on it [email protected]'s original post seems like a gooder idea now😁
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Re: Electric fuel pump

Post by Mr B »

Hi all,

She doesn't have a fuel filter between the tank and pump, only between the pump and carb.

I have a new pump (after market pump) in the box ready to go and the fuel pump is easy to change on an Essex engine (famous last words!) So I'm gonna try that first, ultimately an electric pump is the way to go especially as this car is fitted with a 390 Holley.

Thanks for all the suggestions though guys, it's much appreciated.

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Re: Electric fuel pump

Post by pbar »

All the best with it Wayne, be sure to post back with any results/findings!
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Re: Electric fuel pump

Post by Mc Tool »

I wonder if one was to stuff a bit of air filter foam into that vent hole would it slow down the rate of evaporation 🤔?
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Re: Electric fuel pump

Post by Major_Tom »

Mr B wrote: Tue Sep 27, 2022 10:01 pm and the fuel pump is easy to change on an Essex engine (famous last words!)
The cursed phrase!!!
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Re: Electric fuel pump

Post by SCP440 »

Mc Tool wrote: Wed Sep 28, 2022 5:39 pm I wonder if one was to stuff a bit of air filter foam into that vent hole would it slow down the rate of evaporation 🤔?
Unlikely, it will also be evaporaing through the jets.
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Re: Electric fuel pump

Post by Mc Tool »

Uh ok , I would have thought that the surface area of the fuel in the float bowl would have been much² bigger than the surface area of the fuel in the reserve wells ( area where the jets and air correctors live )......but hey.
Im at a sort of cross roads re my Capri build. I have a choice of either fuel injection ( 3.9 Rover efi with meggasquirt ecu ) or edlebrook performer manifold and 390 holley ......same carb as Waynes 3L essex motor .
IMG_20200124_124258.jpg
Problem is that I just cant get past the traditional look of the big shiny air cleaner right there in the middle.
Fuel injection ticks all the other boxes tho ....performance wise its worth 40 bhp by just bolting it on....probly better economy too,and no evaporation issues but it dont look right 🤔
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Re: Electric fuel pump

Post by Mr B »

Well everyone I think I know for sure what the issue is with my car now, today I went to start her up and as usual she wouldn't go, so I disconnected all the fuel lines on the car from the pump and connected 1 fuel line from a petrol can to the fuel pump intake and cranked the engine over, absolutely nothing came out, so I disconnected the fuel line and got a Calpol syringe and injected petrol directly into the intake side of the pump until it was apparently full, left it for 10 mins, reconnected the fuel line from the can and cranked the engine over, within a couple of seconds the pump sprung into life, reconnected the cars fuel lines and now everything is fine, so for me the pump drying out appears to be the issue, to sum up you guy's were right - it is the pump at fault, I'm just not sure whether the pump is totally to blame or today's modern fuels have a part in this as well.

Thanks for your help everyone 👍

Wayne
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