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Any VAG experts in the house?
BenTyreman - 7/9/10 at 08:32 PM

Skoda Fabia 1.4 TDI, 06 reg. Cranks at normal speed but doesn't fire. Diesel dripping off engine undertray onto the floor and diesel all over the top of the gearbox. Oil and coolant levels normal. No warning lights on the dash. Drove perfect earlier today right up to the point where it was parked up, although there is evidence that the diesel has been leaking for a while. Can anyone shed some light?


A1 - 7/9/10 at 08:54 PM

i like to think id have been more help if the topic was about what I first thought it was...


tomgregory2000 - 7/9/10 at 08:59 PM

the old mans mk5 (06-07 ish) golf 2.0L tdi had a problem like this, drove it parked it up and came out 5 mins later and it wouldnt start, cranked over and everything.

it turned out to be the throttle body unit (fly by wire) which needed to be replaced for a brand new unit from vdub which i think was around £400


nick205 - 7/9/10 at 09:12 PM

I think it's a case of tracking down the leak. As there's fuel on the g/box I'd start top and work down from the fuel rail.


Danozeman - 7/9/10 at 09:14 PM

definatley because of the fuel leak. Gotta be a pipe gone on the high pressure side i think so will be in the head area. Take the cover off and have a look.


Davegtst - 7/9/10 at 09:18 PM

Sounds like you have a diesel leak. The pump in the tank will only work when the engine is cranking on that model. If the fuel is over the gearbox it sounds like the problem may be in the high pressure pump (end of the head N/S) or the pipes to or from it. BTW your engine is a pumpe duse type of injection/engine, the fuel injectors and rail are inside the head.

[Edited on 7/9/10 by Davegtst]


BenTyreman - 7/9/10 at 09:35 PM

Will have a look in the better light tomorrow. Didn't see any fuel squirting under high pressure while cranking. I presume the HP fuel pump is hidden under one of the pipes between the engine and battery? Just follow the metal fuel lines, I guess.


dinosaurjuice - 7/9/10 at 09:39 PM

as far as i know all those engines are PD. i think theres an intermediate pump on end of camshaft which supplies fairly high pressure fuel to the unit injectors. This has a gasket between it and the head which can go i think.

edit: just realised how vague that answer is. think a good poke around under the bonnet is in order


[Edited on 7/9/10 by dinosaurjuice]


Davegtst - 7/9/10 at 09:45 PM

I doubt it's the high pressure side and the pump is on the end of the head, there isn't another one on the crank. I suspect you had a small leak on the low pressure side and it's got a load worse.


zilspeed - 7/9/10 at 09:54 PM

Most of the modern engines use fuel pressure sensors (I know, that's common knowledge, but bear with me.)

In the case of the PSA HDi engine, fuel pressure has to reach 300 bar before the ecu will fire the injectors. 1350 bar is the operating pressure for mine.

I wouldn't be at all surprised if this is one of the operating criteria for your TDI motor as well.

Fix the leak, the pressure will go back up, it'll run.


Daddylonglegs - 8/9/10 at 08:38 AM

quote:
Originally posted by A1
i like to think id have been more help if the topic was about what I first thought it was...


Beaten to it!


BenTyreman - 8/9/10 at 12:31 PM

Tiny leak in a 3" piece of rubber feeding the pump at the end of the head. Must have allowed air into the system, as well as squirting diesel everywhere.

Cheers.


Davegtst - 8/9/10 at 09:02 PM

Woohoo, do i win a prize?


BenTyreman - 8/9/10 at 09:06 PM

quote:
Originally posted by Davegtst
Woohoo, do i win a prize?


Prize would only be to the value of the repair - not sure I can buy a stamp for 25p