'96 A6 Quattro fuel pump

[Grant Lenahan]

I dont know exactly how it works, but I do know that the effect is  
much like what you say.

It goes on, then turns off. I believe this may be related to building  
up pressure then turning off until the motor is running.

I do find that audis ( all of them) start better if you turn the key,  
wait, then engage the starter. This builds pressure and fuel, I presume.

I have not traced wires nor watched the 12v feed go on and off.   
Maybe on a day that cable goes out.....

Grant

On Dec 16, 2007, at 3:52 PM, Kevin Smith wrote:

> Thanks for the input Grant. I'm wondering, do you know if the pump  
> is only energized for a brief moment when the key is turned on?  
> Basically, at the fuel pump fuse in the fuseblock inside the car  
> (driver side dash, at the end), will it show 12v for only a couple  
> of seconds, and then return to zero, or should that fuse remain  
> energized (12v) for as long as the key is on?
>
> The reason I ask is, while testing things, I found that the relay  
> is in fact working, but I still wasn't getting power through the  
> fuse. I tested the circuit and it was showing a short to ground,  
> until I unplugged the fuel pump, then it shows 12v at the fuse, but  
> only for a second after turning the key on, then it drops out. I  
> tried to test the pump itself for a short circuit, but I can't seem  
> to get a reading, so I'm not sure what was causing the short in the  
> circuit before. It could be the pump still I guess, but I'm not  
> sure. Does anyone know the pinout diagram for the fuel pump  
> connector? There are 4 pins, and I would like to know what each pin  
> corresponds to, if possible. I'm not sure if this would be in a  
> service manual like Chilton, Haynes, or Bentley, and I don't have  
> one currently anyway, so I figured I'd ask.
>
> Any help would be greatly appreciated. Even if someone that has the  
> same car could take a couple of seconds to use a voltmeter and test  
> the fuel pump fuse to see if it shows 12v only for a moment when  
> the key is turned on, or if it stays energized the whole time the  
> key is in the run position.
>
> Thanks.
>
> Grant Lenahan wrote:
>> On a C4 anyway, you should hear the pump[ energize then stop when  
>> you  turn the key on.
>> If it is not running, it may be dead.
>>
>> You can hear it really well if you remove the back seat.
>>
>> Grant
>> On Dec 13, 2007, at 2:01 PM, Kevin Smith wrote:
>>
>>