A6 2.5 TDi AFB Won't Start

**philfingers** · 25-03-2009,10:18 PM

Ok I checked the lift pump, it's drawing 4A. Pulled the back seat up but it seemed loudest when I was listening in the OSR arch. Pulled the connections off the fuel filter and it took about 1/3 of a filter's worth of diesel before it was full. I then cracked the injectors (each bank seperately) and diesel was coming out when i turned it over. But wouldn't start? Should the diesel come out if the system was immobilised? Also the lift pump didn't pump any fuel out of the filter unions when they were off as Adamss24 had mentioned. Bit odd it's got a pump tho being a 1999 car.

I got an OBD /USb today and with 409.1 I got the following message

Address 01: Engine
Controller: 4B0 907 401 P2
Component: 2.5l/4VT EDC 0000AG D60
Coding: 01001
Shop #: WSC 02325
1 Fault Found:
17978 - Engine Start Blocked by Immobilizer
P1570 - 35-00 - -
Readiness: N/A

BUT i cleared the code and then tried to restart it several times and no code was then reported.

Any ideas folks?

Phil

ps now disenchanted with 4300rpm at 70 in 5th in my 205!

**snapdragon** · 25-03-2009,11:02 PM

I think there is an anti-shudder valve which closed when you switch off the ignition to stop the car shuddering as the engine stops. It makes it stop dead. This may still be shut stopping the car from starting.I think it is at the back right near the turbo.

**philfingers** · 26-03-2009,08:53 AM

Close to where the fuel pipes run from the filter there are three sender type devices. One with a white rubber boot and spade, one with a JPT (Junior Power timer) connector and a third spade.
Will take a look tonight for the valve you're talkign about. I guess it will be somewhere in the fuel line,

Phil

**snapdragon** · 26-03-2009,12:02 PM

Originally Posted by philfingers

Will take a look tonight for the valve you're talkign about. I guess it will be somewhere in the fuel line,
Phil

It closes off the air intake. I have only read about it, not seen it to be honest.

**philfingers** · 27-03-2009,10:01 AM

the more I think about this it's odd that the fuel filter was only ~2/3rds full of fuel. how can this happen? the takeoff's/ unions are at the top of the filter, there's not even a drain at the bottom of the filter for water removal and there's no visible leaks.... . oh and the car is the right way up!
Couple of Qs
1) So if this a definate that the lfit pump will not/ should not pump fuel to the filter. Ie if I run the pump with the unions off the filter I shouldn't see any fuel coming out?
2) if the small pipes (returns?) between the injectors are weak/perished will these allow the fuel to run back to the tank?

I have an old facet petrol pump for carbs at home. Going to run that from a tank of diesel into the filter and see if that will sort the problem. Runs at around 6psi from memory so shouldn't damage anything should it?????

Since I reset the fault code for the immobiliser it hasn't come back on (tried to restart 3-4 times) so i guess it's a code that was there for a while and I have no present fault.

Phil

**Peter D** · 27-03-2009,10:51 AM

So you have established you do have a liter pump as you can hear it priming but no fuel at engine. I suggest your problem may be in the tank, there are several small pipes associated to the pump and one may have come off or has split. I Suuest you remove the rear seat and remove the tank pump inspection cover and disconnet the output pipe and attach a pipe into a container and prime the pump, if no fuel comes out then you have your problem. If you PM me your email address and a remider of the year and model I send you all the information you will need. Regards Peter

**philfingers** · 27-03-2009,11:26 AM

this is all a bit odd. So far as I could see there isn't any form of inspection cover/hatch under the base of the rear seat. Something is definately running under there tho and pulls 4A! PM sent, thanks for your help so far!

Phil

**Peter D** · 27-03-2009,02:40 PM

They all have a t least one. Remove the seat and the backrest, lift the sound felt on the drivers side and there is a cover. I sent you a drawing ref 60001. Regards Peter

**philfingers** · 27-03-2009,09:23 PM

It started! I checked that there was voltage present on the fuse for the pump when I turned the ign on and also on cranking and there was. With a fully charged battery having filled the fuel filter 2 days ago it started after spinning it over for about 15 secs. There were lots of air bubbles in the clear fuel tube.
Tomorrow I will try and get a look at the lift pump. The return pipes from the injectors are in poor shape so I intend to do those at the same time as do all the belts tomorrow, with water pump and thermostat.
Must be down to a leak in the pipe work I guess. Tho it never drops any oil or fuel