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Fuel pump and fuel pressure


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Hi everybody,

looks like my fuel pump on my US '77 S1 is at the end, stopped running on and off and returns to live by knocking with a screw driver handle on it. Electrical connections are good. I am sure it's the internal that is gone now. My question now, the car runs great with the NOT original fuel pump that is in it, I would like to stick with something similar ( see pic). What kind of pump do I need or you guys recommend, also in regards of the fuel pressure, what is the max. pressure or what is recommended? I read some horror stories of high pressure fuel situations and starting all kinds of leaks. Any part numbers for fuel pumps that would work?

Thanks for any hints and help!



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The horror stories are mostly on the turbo which uses a high pressure pump and pressure regulator. But the S1 would use a conventional pump for carbs, which produce a low pressure, 2 or 3 PSI.

But are you sure its faulty? If the float chambers are full and needle valves closed the pump would not need to do anything. I am not sure if this type of pump stops when its not having to move any fuel but it might. Is there a problem with the car?

If replacing, any pump which is designed for carbs without turbo would work, but you may want to identify it and replace with the same so it fits the bracket and hoses.

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It is possible to take the SU pump apart and clean the points to get the original pump running again. Over the weekend I was watching a Youtube video of MG specialist who, with the pump on a workbench did the entire strip down, points clean, reassemble and test in under 10 minutes, videoed in 1 take.  list 2 fuel pumps AZX1307EN which is 2.7psi and the AZX1308EN  which is 3.8psi. They are "electronic" and no longer have points so no click click click at start up but from the outside they are identical to the originals. UK price direct from them is £85 probably plus VAT  carriage and all the other stuff.

Normally Aspirated - and lovin' it!

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