Re: Crazy, isn't it! (archive)

Just had the pump etc out (of the tank, I've got a 735) and the output of the pump has a fuel pressure regulator (looks like a mini gas regulator like you'd get on a barbque gas tank) before it goes to the hose - if the diaphragm has
relaxed, maybe you're getting an oscillation in there. Try finding the pump and listening to it while someone races the engine for you - the extra petrol demand might kill the oscillation, and if it does you know it's the regulator.

Also must remember that
1) roller pumps are prone to wear and noise - the rollers can get looser with age
2) the rollers should be lubricated by the petrol going thru the pump (the whole motor is immersed in petrol - no oxygen so no explosion. NEVER run a pump without petrol going thru it - can cause a residue vapor explosion)
3) they can get rust if there is water in the petrol
4) they can theoretically suffer from bubbles (in the body) if the body is mounted horizontally
5) they MUST have the inlet filter gauze in place to stop clogging and/or wear - if you have an externally mounted pump, have you checked the inlet filter in the tank?

I must admit, both my BMW EFI motorbikes have the original pumps after 18 years...

Max Fretter

>>I mean, with the pump that came with the car and the one that I replaced about 4 years ago, this next one would be the third.

Anyhow, just called BMW service here and the "service advisor" mentioned that the "regulator", instead of the pump itself, could also lead to the buzzing noise...any idea about that one?

I think it probably isn't something as simple as a clogged fuel filter, no? I don't think I'd be that lucky...

Richard

Follow Ups:

That could be a problem... R.Mui 21:30 12/06/2000 (1)
- Re: That could be a problem... Max Fretter (NZ) 02:25 12/08/2000 (0)

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