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Discussion Starter #1
I have a 2002 VW Passat V6 2.8L 4Motion. Yesterday while going down the highway, I suddenly just lost acceleration, nothing was happening when I pressed the gas pedal, the car started to decelerate, and I had to pull over on the shoulder. I switched off, but when I tried to restart, the car would just crank and tumble over, but not start. I had to get towed home. Any idea what might be wrong? Please help
 

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Sounds similar to what happened to my Passat at 72k miles. The fuel pump went bad. With it quiet, turn the key to Ign On/Run position (not crank/start) and see if you hear the pump run for a couple of seconds to prime the lines.
 

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I agree that the pump probably went out. Not a certainty, but that's what I would suspect first. Hopefully the tank isn't over about half full, because to replace the pump, the pump access cover has to be removed.
 

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Or, cam position/engine speed sensor. Did it sound normal when you cranked it? If it cranked too fast, perhaps the timing belt.
 

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If the car has been sitting with the doors closed for a few minutes, the fuel pump runs for a couple of seconds when you open the driver's door, too.

Presuming cranking sounds normal (which would indicate the timing belt is ok), do this:
> Crank for 7 seconds continuously. If it's the engine speed sensor (ESS), the car will start and run. The ESS usually goes flaky, rather than outright failing, so this probably isn't your issue, but the test is easy.
> Remove the fuse box cover. Pull fuse 28, the fuel pump fuse. Take two measurements:
>> One side should show 12 VDC (with respect to ground) when you turn the key to "run."
>> The other side should show a low resistance (5 to 20 ohms, if memory serves) to ground. That's the resistance of the fuel pump motor. If yours measures infinity/open circuit (like mine did), then your fuel pump needs a new one.

The fuseholder test works because the fuse is the last thing in the circuit before the pump. The fuel pump relay is upstream of the fuse, odd as that seems.
 

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Pull fuse 28, the fuel pump fuse. Take two measurements:
>> One side should show 12 VDC (with respect to ground) when you turn the key to "run."
True, but briefly. When cranking (Start) there should be continuous (cranking ) battery voltage. For me, the most convincing test of the whole circuit, except for the pump motor itself, is to disconnect the FP connector and then jumper the outer two pins of that harness connector to a standard 55W headlight bulb. If that lights up bright while cranking, but the pump won't run, you will have proven the circuit to be OK except for the pump, which therefore is at fault. However, as FrescoGreen01.5 mentioned, if you find an open-circuit between the fuse and ground, likely the pump has gone bad.
 

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Wasn't there a bad batch of fuel pumps in the 2002-2003 model years? If a previous owner often let the fuel tank get very low, the pump could have been heat damaged.
 

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I think it was the 03, but only FWD.
 

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undo the fuel line under the hood before the injectors and crank the car. if the fuel spills out then pump is ok, if not, id suspect the pump.
exactly the same thing happened to me few years back.
 

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Discussion Starter #11
Thanks everyone, it was the fuel pump. i took it to an auto shop, they did a diagnostic test, checked the fuse, relays, and surely enough when they disconnected the fuel line to the engine, and tried starting the car, no fuel came out. Got the pump changed and its working again.
 
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