Slow fuel pump?

Talk about the E-Type Series 2

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Louis31
Posts: 1
Joined: Thu Jan 25, 2018 11:09 pm
Great Britain

#1 Slow fuel pump?

Post by Louis31 » Mon Feb 05, 2018 12:31 am

Attempting to get my fathers 4.2 series 2 running again after a long 8 years off the road.

After a bit of crankingthe car didnt seem to be getting fuel i checked the glass fuel bowel it was full so i opened emptied, cleaned and put back together. Started the ignition to allow the fuel pump to fill the glass bowel which it did but very slowly i could hear the pump clicking slowly round. Timed on my phone between each click and it was about 7sec. Which sounds quick on paper but it really doesnt sound quick enough to me.

Problem is ive never heard a etype pump operate correctly and always remember my dad leaning back giving it a good tap every now and then.

To my mind the pump should fill the glass bowel and 3 carb bowels in a few seconds then stop once full ready for the car to start.

Once i let the pump take an age to fill the system the car seemed to start reluctantly until i think the pump couldnt keep up then cut out.

Think i need a new pump or a rebuild. Any thoughts or advice would be appreciated

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abowie
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#2 Re: Slow fuel pump?

Post by abowie » Mon Feb 05, 2018 2:28 am

What you are describing sounds like a fuel pump functioning correctly. They will pump up to pressure, clicking quickly, and then stop.

To check the pump, disconnect the fuel hose from the filter, point it into a jar and get someone to turn the ignition on. You will get a continuous flow of fuel if it running correctly.
Andrew.
881824, 1E21538. 889457. 1961 4.3l Mk2. 1975 XJS. 1962 MGB
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia

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Paul71a
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#3 Re: Slow fuel pump?

Post by Paul71a » Mon Feb 05, 2018 6:10 am

Had one of those annoying “cant find the fault” scenarios last summer, which turned out to eventually be the pump in my S2 on its way out... replaced it and all was fine again....

A click every seven seconds when the bowl is empty sounds much too slow... it should click like a ratchet until it’s full, then slow down and stop once the system is full and pressurised.
Paul Brazier. S2 FHC 1970, silver with blue leather. Oh, and a S1 prototype Lotus Elise and a Ferrari 488 GTB

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christopher storey
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#4 Re: Slow fuel pump?

Post by christopher storey » Mon Feb 05, 2018 8:22 am

That is much too slow , but caution , it may not be the pump at fault : if the system gets partly blocked, this is how the pump will behave. First I would try the flow test already suggested, then I should disconnect the delivery pipe from the tank at the filter, and blow compressed air down it back towards the tank to ensure that the pipe is patent

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JagWaugh
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#5 Re: Slow fuel pump?

Post by JagWaugh » Mon Feb 05, 2018 8:36 am

Sounds like a delivery problem to me.

Generally, the pump should click about every half to 3/4 second while filling an empty bowl.

Disconnect the line _into_ the filter and turn the ignition on. If the pump clicks faster then you may have a blockage downstream from the carbs, if the speed doesn't change then your problem is between filter and tank.

Pressure should be around 3 psi, but less than 4, and flow should be about a pint every 15-20 sec iirc. Volume should be around 30 Gph, which works out to about a pint every 30 sec. (units are imperial) Your 7 stroke/min is so slow that I suspect you've got either a duff pump, or a blocked fuel line - probably the latter.

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