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Discussion Starter #1
I offer this little blog of info on the chance it may help others.

The problem with modern cars is that they've become overly complicated. Take for instance the morning I prepared Joose for the morning commute. Nothing unusual, warmed him up and parked him on the street in the direction Jeanne needs to go.

But when it came time to leave, Jeanne accidentally triggered the alarm system, I happened to have the spare key and both of us went about turning off the alarm. I only mention this because at first it seemed related.

I thought we had accidentally triggered the immobilizer system as the car started briefly then immediately shut down. This had never happened before and I wasn't familiar enough with this security device, so I assumed that it had shut down the vehicle. (didn't know to look for a dash light indicating this)

So I came here to review how this was reset and proceeded to follow the basic instructions of disconnecting the battery for 10 minutes. However this didn't solve the problem, the car still would not start. It cranked but no ignition. By this time I was familiar with the immobilizer dash light and saw it wasn't on.

So now to troubleshoot. First up, spray starting fluid into the intake. The engine burst to life for a brief moment, so I had a fuel feed problem.

I proceeded to test the pump's fuse and relay (it's electrical) and they worked. I tested the wiring going into the pump and that was good, so I proceeded to extract the fuel pump. (fairly easy task actually)

I bench tested the pump and it worked, however I noticed one of the electrical clips to the pump was looser than I would prefer so I improved that connection, reassembled everything and the car started right up. No real surprise there at this point.

I then did a pressure test of the fuel pump and it was putting out 50 psi - so that seemed good.

Test drove it on errands for the rest of the day and never had another problem.

I'm not 100% certain this problem won't reoccur, at which time I probably will break down and replace the fuel pump. (I just hate replacing parts without certainty of their failure)

Maybe the Alarm had something to do with the failure, it's all computer controlled, perhaps we stumbled upon a bug in the software (Bug bug?) - but I have my doubts.

Anyone else run into this sort of problem?
 

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Have you scanned the car for trouble codes? Please post; any trouble codes, you find.

Keep in mind with electric fuel pumps; heat can really affect their performance and the fuel pump 409 relay is a classic problem as well. I have seen some pumps work fine; when the car is cold and once it gets hot, the car wouldn't start and the engine ran horrible under load (when we did get it started). In the same pump; the psi was in spec but it was not able to maintain correct fuel volume (fuel starvation). Lean trouble codes; also, thrown in relation to the problem. In that case: if I had done a fuel volume test, that could have been a clue as to the problem with volume vs. psi readings I was seeing. In another case; I saw good psi rating, when the car was running but it was not able to retain residual pressure with the engine off. In that scenario: the psi went to zero, the residual spec should be maintained for 10-15 minutes. That car, became harder and harder to start; as the residual pressure was non existent and the pump struggled to pressurize the system, before starting (cycling the key a couple of times; helped get the pressure up to normal).

So, as you can see: there are quite a few fuel delivery failure scenarios; that do not conform to a conventional @ idle psi test, that most people perform.

How many miles on the car, what year, engine and has the pump; ever been replaced? If it has what was the brand and part number? We have seen allot of non oem aftermarket pumps; give owners drivability problems, it is best to stick with oem VDO/Continental, Bosch or genuine VW. Give us more info about the car; check for trouble codes and we can go from there. Thanks.


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Discussion Starter #3
I should have mentioned one of the first things I did was scan for codes and there wasn't anything.

The ambient temp was a cool morning. The engine was fully warmed up but that wouldn't impact the pump temp directly.

The car JUST turned 180k and as far as I know it's the original pump. It looked like it, it had VW/Audi markings on it as I recall.

It's a 2001 2.0l with Automatic.

There have been no performance issues with the car, never had a problem starting it.

The only other anomaly is a strange power loss when driving at freeway speeds and the fuel supply is less than 1/4 tank. It's been doing that since I got it (4 years ago) and it only happens when the tank is low, so naturally, I mostly try to fill before then.

The power loss is so brief, it almost feels like you hit a bump in the road.

The PSI test I did was just direct to the pump, didn't have the engine running. Mostly I wanted to see what the pump was delivering when just activated.
 

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Well, @ 180k on a original pump and 15 years of running all the time; it is way over due for replacement (both time and mileage need to be taken into consideration). I would go with a oem Bosch or VDO, Amazon has excellent pricing on both. The Bosch pumps are nice; because they have integrated the fuel tank level sending unit into the design (no need to buy it separately) and they include a new tank lock ring seal. A new fuel filter and fuel regular; would be good to thrown in during the swap; for good measure. The high speed/load; momentary loss of power, sounds like what happens with lack of fuel volume on a weak pump, as well as issues when the fuel tank is low.

You can look up the correct Bosch fuel pump part number for your car here: be sure to use your engine code; to confirm the correct pump for your car:

http://www.boschautoparts.com/en/


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Discussion Starter #5
Great advice - now that the car is back and running the pressure is off so to speak, but I'll get one coming and have it in inventory.
 

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Discussion Starter #6
Interesting to note that my pump doesn't look like the OEM Bosch pump. I wonder if it's been replaced? I thought it had an Audio logo stamped on it.

I'll have to wait for it to come home tonight to get the data off the top but the one I have looks like this




And this is the Bosch one.
 

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There have been many different designs over the years; Bosch aftermarket fuel pump designs are being streamlined. I believe they're doing this to reduce manufacturing costs and make them compatible with more vehicles; thus, they do not have to make so many different fuel pumps. This can also be seen; by the integration of the fuel level sending unit, and eliminating a separate part for this.

Keep in mind that there are different fuel pumps for different engine codes and different years; be sure to measure the size of the lock ring; I have been told a major difference of the pumps is related to either a plastic or metal fuel tank.

When you get a chance take a picture of the top of the fuel pump and any information that is imprinted on it. We should be able to identify who made the pump and if it's original; by seeing this information. Thanks.

PS: if you want to confirm that you're getting the right pump; you might contact Bosch technical support with your VIN number and engine code, they are excellent, responsive, and are very helpful folksl:

Contact Us
888 715 3616
IN NORTH AMERICA
8AM - 5PM CST MON-FRI

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Discussion Starter #8
I'll get the part number off the one currently in the vehicle. None of the parts suppliers ask for engine code however. (like PartsGeek or Amazon)

Just engine size (though they often list the same pump for 1.8 or 2.0)
 

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Yeah, when looking at your old one; many aftermarket pumps will have stickers or other marking on them but use VDO or other branded plastic bodies. The internals made by someone else; making the internal pump but not the plastics or just putting another brand oem pump in their box with their sticker on it. Just assume any pump under $100 will be low quality junk; go oem VDO, VW or Bosch, you get what you pay for.
Take a photo of the top and hopefully; we can identify it.

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There should be a thread on here somewhere about the difference in engine codes even within the same years. You will def need it like billymade had posted. :) Sometimes "general" parts searching can be misleading and inaccurate...best to go by part number or engine code with Beetles.

I just wanted to chime in that you are going to need a fuel pump sooner than later. A loss of power when the fuel is below 1/4 is your indicator. Fuel pumps have to work harder the less amount of fuel is left. So I am glad you're getting one for inventory's sake. :)
 

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Discussion Starter #11
Thanks, as it turns out I've some time on my side as the dang coolant pipe has sprung a leak. (Why couldn't it have been one of the rubber hoses??)

Now I have to focus on fixing that as well. Such is the life of an old bug I guess. :(

Know of any good guides to replacing the coolant pipe? I've searched here but to no avail?

I'll post a request on a separate thread as well.
 
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