Re: Easy Staring with Fuel Pump Prep Run

[ti@amb.org (Ti Kan)]

Matthew Caprio writes:
> I wrote:
> >When turning the ignition key to
> >the on position, the fuel pump relay receives power and it
> >is designed to briefly run the pump to pressurize the system.
> >However, I have also noted on my 4000 that this doesn't
> >always happen.  Probably a flakey FP relay.
>
> I have experinced this "flakey" behavior on all BMWs and Audis with CIS--
> sometimes FP runs on turned key, sometimes it doesn't... I always imagined
> that it has a pressure sensor, and if the accumulator is already up to
> press., then it doesn't bother turning the pump on again... Try this by
> turning your key to run, then off, then run and off, and so on, usually it
> only does it the first time (charges up accumulator?)  but maybe a time
> delay in the relay???.. Don't know where pressure sensor would be though,
> just checked bentley and couldn't find it...

That's because there is no such thing.  There is no sensor of any sort
related to the fuel pump relay.

-Ti
96 A4 2.8 quattro
84 5000S 2.1 turbo
80 4000 2.0
-- 
    ///  Ti Kan                Vorsprung durch Technik
   ///   AMB Research Laboratories, Sunnyvale, CA. USA
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