Mercedes fuel pumps

[WILMAN]

----------
> From: Martin Easterbrook <martin_easterbrook at yahoo.co.uk>
> To: diy_efi at efi332.eng.ohio-state.edu
> Subject: Re: Mercedes fuel pumps
> Date: Friday, April 23, 1999 10:34 PM
> 

I think the Mercedes runs the Bosch KE-Jetronic system which operates at 
a much higher fuel pressure.




> Mike,
> 
> I've done this type of thing in work with some Porsche 911 Turbo fuel
> pumps as a cheap way to get 20bar fuel pressure for some fuel injector
> tests.
> 
> I burst tested a pump first (in a safety cell) to check if it would be
> safe.  The burst pressure was 35bar.
> 
> I know of several people running series electric pumps on race cars to
> get high fuel pressure (= better fuel atomisation from the injectors)
> but I have never heard of a setup like this on a road car, as most
> road cars only run 2.5 to 3 bar anyway.
> 
> I could see a point in connecting them in parallel, particularly for a
> high capacity engine that needed a lot of flow.
> 
> I think the failure you saw is most likely to have been caused by a
> faulty regulator or a blockage in the regulator reflow line.
> 
> Martin
> 
> 
> 
> Mike Morrin <mikem at southern.co.nz> wrote:
> >
> > I was in at a local shop today, and they had a 1990 Merc 560SE (or
> some
> > such model) on the hoist, with fuel spewing out of one of the fuel
> pumps
> > (everything switched off).
> > 
> > The car has two standard looking Bosch pumps, but they are plumbed in
> > series, so that the outlet of one pump goes to the inlet of the
> other.  In
> > this case the crimped join in the case of the second pump had
> apparently
> > burst.
> > 
> > The car had probably sat for a few weeks before the fault happened
> (stuck
> > pressure regulator?)
> > 
> > So why put two standard pumps in series?
> > 
> > Is the aluminium body of the pump really rated to take the outlet
> pressure
> > of the other pump?
> > 
> > Anyone else seen a failure like this?
> > 
> > regards,
> > Mike
> > 
> > 
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