Fuel pump problem.

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CaliMorris
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Fuel pump problem.

Post by CaliMorris »

I finally have everything all together, but i suspect that the fuel pump is not working properly. It clicks very loudly and quickly, and I feel air coming out of the other end of the fuel line, but no fuel ever comes out. Maybe it isn't powerful enough? It stops almost the instant that I tightly cover the fuel line with my thumb, and the air coming out is not nearly as powerful as I would suspect it to be, as I have only worked on modern cars before now.

I saw on another old thread that I just had to undo one end of the fuel line and wait for the fuel to come out, no priming necessary. But I seriously doubt that it takes more than 15 mins to pump fuel from the tank to the carburetor.

Any ideas?

mogbob
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Re: Fuel pump problem.

Post by mogbob »

Is the pump the original i.e probably untouched ?
From your description the points / electrics appear to be working.Is the filter clean/ not clogged ?

If the pump is old and untouched, as soon as you start stripping it down you have to consider the age of the washers/ seals.
Putting the originals back may not produce a leak proof seal.It is possible to wash out a clogged fuel filter ( part no.AUA1464 )
but they are fairly delicate and may have/ might split in the process of removal.The filter washer is part no.AUA1442.

It might be the diaphragm that has split, the originals with age and the use of unleaded petrol, give up the challenge after a while.
You can buy parts individually from people like www.burlen.co.uk or buy a complete overhaul kit for a AUA66 fuel pump.On strip down you may find that although the points are "working " they may also be worn and be near their end of life.

Quick fix... is to purchase a replacement pump but if you are confident and take your time rebuilding an SU pump is not too difficult, just follow the instructions provided.
Bob
MarkyB
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Re: Fuel pump problem.

Post by MarkyB »

It sound like air is being drawn in on the suction side, assuming that there is enough petrol in the tank of course.

"Once you break something you will see how it was put together"
bmcecosse
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Re: Fuel pump problem.

Post by bmcecosse »

As above -it's working fine! Pumping air instead of petrol. So - is there enough fuel in the tank? The pick up pipe may not be reaching down to the base of the tank - add some more!
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CaliMorris
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Re: Fuel pump problem.

Post by CaliMorris »

cleaned the whole thing out and it works well now, clicks pretty slow once it starts working on fuel, but I think that's normal.
Now the S.U. carburetor keeps overflowing, so I am going to take apart the float valve, clean it, put it back together and see if that fixes it.

bmcecosse
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Re: Fuel pump problem.

Post by bmcecosse »

Well done - often the way with a car that hasn't been run for a while.......
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CaliMorris
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Re: Fuel pump problem.

Post by CaliMorris »

fuel system is all worked out now :D
carburetor is probably going to need some calibrations though.

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