Our 2.5 Tdi broke..does my mechanic know what he's doing?

QEDMP87

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Evening All!
We own a '99 141k mile 2.5 Tdi Avant Quattro. Recently it had started cutting out right after starting and then the central locking failed (probably unrelated). Then on its way back from a 140k service at our local specialist it broke down having cut out at a cross roads and has failed to start since.

After suggesting the tank fuel pump, fitting a new one and the car no longer starting. My mechanic now "thinks" it's the fuel injector pump because no fuel is being "sucked" from the tank when the engine is being turned over. Since this is a £1000 part I'm a tad apprehensive to just go.. yeah slap a new one on!

Soooo audi experts could it be the fuel injector pump? What is the tank pump supposed to be doing? I thought that was the low pressure pump making sure that there was sufficient fuel engine side....

Anyway a few questions I'd be really glad for your help;

Is the immobilser attached to either of the fuel pumps?
Can I isolate the problem to the fuel injector pump?
How can I tell if the tank pump is working okay?
I hear about a fuel pump relay.. could that be the problem?

I'd be really grateful if anyone could help!

Many thanks in advance!!!
 
Common fault sadly. The injector pump is expensive and good used ones are rare.People are known to scrap their cars for needing the pump done.

Sorry to be the bearer of the bad news
 
Has the ecu been scanned for faults using something like Vagcom ?

The ECU has been scanned but I can't remember the exact codes, one relating to the immobiliser (I think) and one relating to an engine mount. I'll get the exact codes tomorrow.

Hopefully more info tomorrow!
 
yes sounds correct, but i managed to get mine rebuilt and refitted for just over £800 so shop around
pbasher.com are a reputable supplier or if you live anywhere near stoke i can get number for garage i used
 
Hang on !!!! you said there was a error code about the immobiliser. Well if there is a fault with that you'll get the exact symptons you describe.
 
It's a 2000 on a V Reg. Looks a bit like this...

2144348996_daff5c22d6.jpg


I was wondering whether the immobiliser was attached to the fuel pump especially after the central locking went the week before but if the fuel pump isn't attached to the immobiliser then I guess that error code (if I'm remembering correctly) isn't related...more info tomorrow guys thanks for the thoughts so far! If you can think of anyway I can isolate the fuel pump do say!
 
If you have a immo fault; your motor will start then immediately stop just as you have said in a previous post. All the immo will do if it fails, is stop the main injector pump anyway so I'd investiage the immo error code first if it was me. Before I even went anywhere near the fuel system.
 
I suspect that if it IS an immo issue, its not starting after the pump change as the pump wont be running for long enough to reprime the fuel system.

Does sound immo related, and if theres a fault for that, i'd go there first.

Where abouts are you based?
 
Hi there, if there is a IMMO problem, the warning lamp will flash and the car will start but almost immediatelly stop. If there are no other faults logged in i would ask someone with Vag-com/VCDS do a log and check if the pump controller is getting power from the ECU(in basic settings block 15/16 - dont remember wich one but you will see it !). It should be about 12V . If there is power to the pump's controller, i would look elsewhere, if there is no reading/low voltage i would have the pump refurbished by dieselbob. Just to save you some time, the VP44 are notoriously rubbish at bleeding and the tank pump is there just to prime the main chaimber in the tank so i would get someone to tow you round the block with a towbar while the engine is spinning in 2nd in gear(like when you wanna tow start-it). Thats the best way to bleed said pumps. If the car starts then its air ingress if it does not chances are the pump is knackered. You could also try a squirt of Easy start/brake cleaner spray, but too much and you can hydrolock the engine ! If the engine starts and runs for a few sec then its fuel related...
 
Afternoon again!
So the saga continues... my mechanic has now told me that he suggests we scrap the car because a new fuel pump is so expensive - I thought a diesel audi at 141k was only just run in!! I've managed to get an error code from him...

17978

Does anyone have any thoughts as to what this might be?

My mechanic has also told me that he won't put a rebuilt F&I pump on the car... needless to say I'm slightly annoyed and have decided to take the car elsewhere. I'm thinking about RSD in Daventry as they are only a couple of miles from my house.
 
http://wiki.ross-tech.com/index.php/17978/P1570/005488

Possible Symptoms


  • Engine starting but stalling immediately
Possible Causes


  • Key(s) not matched
  • Instrument Cluster not matched
  • Engine Control Unit (ECU) not matched
  • Engine Control Unit (ECU) Power Supply faulty
Possible Solutions


  • Check for Fault Codes in Immobilizer itself (part of Instrument Cluster in many cars, but separate Immobilizer Control Module in some)
  • Check Immobilizer Measuring Values (usually in Instrument Cluster OR Immobilizer Control Module)
  • Match Key(s)/Instrument Cluster/Engine Control Unit (ECU)
  • Check Engine Control Unit (ECU) Power Supply (Relay)
Special Notes


  • If no other immobilizer related fault codes are stored and the immobilizer related meas. blocks are fine except Engine Start not allowed, in rare occasions it helps to try cold-booting the car. Remove both battery cables from the battery. Short the battery cables together (away from the battery) for about 15 seconds. Reconnect the battery. (Example)


Would said mechantic want to be buying your motor off you cheap by any chance ?
 
As said, thats an immo fault, not a IP fault.

Its odd that its just broken though, do you have a spare key you can try on the car?