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Old 06-23-2003, 04:43 PM
treynolds treynolds is offline
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Join Date: Jan 2002
Location: Salt Lake City, Utah
Posts: 9
On the Fuel pump the Red (negitive) and Black (positive) were not reversed. Apparently this was not an uncommon practice on older European cars, or so I was told by a friend who worked as a mechanic when he was in school.
I was confused when checking the voltage because I assumed that Red was positive and Black was negitive, and hooked up my VM as such. Obviously when the ignition was turned I did not see any voltage, so I suspected the Fuel Pump Relay. After wasting time checking the relay I connected the VM correctly and verified that I had voltage and that the pump was faulty.

I was testing when the car would not start and if I remember correctly, voltage is only supplied to the Fuel Pump for one second when the ignition is turned, this primes the engine to start. If the engine does not start ( 0 RPM's ) either the Fuel Pump Relay or someother electronics module stops the voltage to the Fuel Pump - I believe, but did not confirm that if the RPM's are greater than zero (engine starts) then continious voltage is supplied to the pump.
(I also found a note about this on a schematic.)

I believe that 12V is correct for the pump.

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