HELP PLEASE - Engine Keeps Cutting Out!

[batteryboy]

Hi All,

I've a real problem and would really appreciate some help.

The short story is:

Randomly, my engine just cuts out totally, no warning lights on dash such as ESP, Glow Plug, or ECU, that usually come on when a problem occurs. I can start my car and more often than not, it will drive ok, but then just cuts out. If I turn off and re-start it runs for about a minute or two, then stops. this goes on and on.

Ironically, but probably totally coinsadentally, if I turn the AC off, it seems to keep going, but if I then turn the AC back on once the car is running, it keeps going!

The long Story is(but bulleted)
I got this car in June 2010 at 60,000 miles. I've took it to my usual dealer for a warranty check over and they said it was 100%, even though I said I thought it was down on performance and fuel ecconomy was poor. They have always said there was no problem, but then I got the Injector recal in the new year of 2012. This seemed to solve all the problems of poor performance, low fuel ecconomy (37MPG ave) and poor starting. Then it started to run rough again and seem to have a miss-fire and sometimes fealt in traffic it was running out of power, but never stopped. The dealer still said there was no problem but when it was serviced a few weeks ago (approx 110K miles), they replace a cap or valve as they said there was a code stored for low turbo boost. Now it has this cutting out problem!

I'm wondering if it is something to do with any of the following:
AirCon problem
Key / imobaliser problem (altough I've tried both keys and same issue)
Fuel pump problem
EGR
Turbo

Or, is it just a cold temp running sensor?

I'm currently awaiting the dealer to call me back after trying to get some Tech help from Audi H/O

Mycar is:
A4 B7 June 2007
2.0 TDI 170
S-Line
SE
Quattro

112K miles Full Dealer Service History

Any Help would be greatfully appreciated.

Dave

[c4a5er]

you really need to check if there are any fault codes stored again otherwise it'll just be guesswork....

[batteryboy]

Thanks for the response.. Yes, That's my thoughts & understanding too.......... Trouble is, is that I've been in the motor trade all my life (since 84) and was originally on the spanners and now in parts & manufacuring and I am starkly aware that dealers no longer employ mechanics as the overall manager at my local dealer had to conceed today! Unless Audi send them a note or thier computer tells them there is a problem, they are lost..... ;-)
I'm currently waiting for them to come pick it up but I'm hoping to get the codes read tomorrow morning before they have it as I no longer trust the dealers, but as they've serviced it for the last 2 years including a few weeks ago, I'm hoping they will take some rsponsability, especially as I've been telling them there's a problem for months!

[a8 tech]

lol rubbish

god i wish some one at audi would send me a note how the f@@k have i survived for 20 years

[batteryboy]

lol rubbish

god i wish some one at audi would send me a note how the f@@k have i survived for 20 years

Not sure what you think I've stated is rubbish, but it sonds like you are an experienced guy, and not a dealer technition.

It's the proper mechanics/Technitions like you sound you are that can think problems through for themselves with common sense and experience...... In my experience, it's the "Dealers" that lack the intuition to diagnose unless the have a bulliten from the manufacturer, or the Diagnostics system telling them.

That asside..... do you have any idea in your experience what my problem could be?

[a8 tech]

I am a fully trained dealer master technician and yes I do
Post a scan
It's likely to be engine speed sender or voltage supply relay to the ecu



Sent from my iPhone using
My fat fingers

[a8 tech]

Or the fuel is contaminated with soot
Drain the filter and inspect the fuel



Sent from my iPhone using
My fat fingers

[batteryboy]

Hi A8 Tech,

Thanks for your further replies.

I fill up with fuel usually 2 - 3 times a week, so the system is clean, apart from the obvious possabillity of dirty fuel going in.

As for the other possible problems.....

Is it at all plausable that any of these issues could have been caused by either:

A: something the dealer technition did whilst fitting the new injectors or the V03G 129 061C Vacum unit (this was suppossed to have fixed all the problems when it was serviced a few weeks ago!)

B: as a result of the vehicle being driven for 40,000 plus miles with the defective injectors when the dealer couldn't find a problem until the recall

It seems to be something shutting the fuel system down, but I appreciate it's hard to pinpoint these issues sometimes............ but it's all too much of a coincidence!

I'm going to have the vehicle read for fault codes by an independant VAG specialist (originally VAG Master Technition) to see if I can get a view before the felaership comes and picks it up.

[batteryboy]

The other thing I thought it might had been was a problem with my ignition key, but it still does it with my spare, or a problem with the vehicles imobaliser.................. A bit like certain vehicles that if you perform a battery change, you have to go through a sequence of re-programming the car or it will start up, but then just cut out after a matter of seconds to prevent theft. I n most of these cases, you can perform the reset by simply locking and un locking the car via the fob.

Also.......... and this is a interesting one..................................

As you have been able to throw up a few suggestions to the possible problem, how come it took most of the day for the dealer to call me to say that they had all had a think and a chat abou tmy problem, but were totally lost as to what it could possibly be!! ;-)

[Major Clanger]

Back when dinosaurs ruled the earth I had an Alfa 75 Veloce which developed a problem very similar to your A4. The cutting out would occur without warning (therefore potentially dangerous) and only when the engine was hot. After much investigation it turned out to be a relay that powered up the Magnetti Marelli ECU (and so much along the lines of what A8 Tech suggested).

Something inside the relay obviously went open-circuit when it got too hot. A simple and cheap change and I had no problems afterwards.

Hope yours is something similar.......