HELP!! please!! a4 2.5 tdi wont start

HI folks, i am at my wits end, i am selling a psi tuning box for the audi 2.5 tdi v6, its the vp box,
My nightmare started last night when a chap arrived to buy it and wondered if i'd fit it for him..... i thought nothing of helping him out with it, but when we fitted the box, he wasn't happy that the performance was of any significant increase so we removed the box connect everything the way it was and now his car wont run!!!!!! GREAT!! so now i have some1's a4 sat on my drive that wont run, the problems i can describe are as follows, the car will fire and run for about a second and cut out, then if you try it again straight away it wont even fire, then if you leave it a second or two it will fire and run for a second and cut out, now the guy said that the orange light with the car and a picture of a key on it never came on before when you switched the ignition on, but now it does, it goes out when you turn the ignition on, and wait for glow plug light to go out it does too, but the damn car wont run, i am panicing that ive wrecked this guys car!!! please can some1 shed some light!!! have i possibly wiped the code out the ecu, or damaged the immobiliser!!!the car hasn't run since this occurred!! help me please................ many thanks steven.

Presumably the car was running OK before removing the box. All I can suggest is that you check the connectors carefully for possible damage following box removal and re-instatement of original setup. Although I have no experience of tuning boxes, I do dabble a lot with electronics/computers and 99% of problems seem to be associated with connectors and/or wiring. Have you tried the box back on your own car, or are you worried about the same thing happening?

Thats an imobilsser problem, try moving the steering wheel in and out a bit, then leave it more in than normal,see if that works.They have a habit of stretching the reader wires.
Also try the spare key

HTH

thankyou for your reply, well i've actualy sold my a4, due to being sick fed up with it, when i owned it, the garage was its second home!! it was the afb eng code, which is renound for injection pump failure etc, which i had, and had to replace, £2200 quoted from main *******!! but got an independant specialist to fix for £1400, still a hefty blow, so ave lost alot of confidence in audi dealers due to other issues that i had with them, which would prob shock most, but thats a diff story.... anyway rant over......
So here i am now having got rid of that 2.5 nightmare to having someone elses sitting on my drive, think im jinxed!!! :confused:
I've jst spoken to a mate who's a very well respected auto electrical technition, who said that this very problem happened to him a few weeks ago, when a customers A4 in which he renewed a battery on, had the same symptoms, he had to trailer the car to audi and get it recoded, due to the key and the imobiliser going out of sync!!!! i prob had the battery disconected three or four times in succession!!! so i am praying this is the case, i know this was i private deal but i feel only obliged to pay for the computer recoding, as i feel responsible for said problem.....:aargh4:

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Originally Posted by audimad

Thats an imobilsser problem, try moving the steering wheel in and out a bit, then leave it more in than normal,see if that works.They have a habit of stretching the reader wires.
Also try the spare key

HTH

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Thankyou for your reply i will try this jst now, unfortunatly i only have 1 key the guy lives about 40 miles away, this is a monumental mess, that only i could of engineered to perfection..... cheers lads...

The first thing you need to do is find some way of getting the ECU read for fault codes. Did you disconnect the battery when fitting the tuning box? The immobiliser coding is between the ECU and the instruments, I can't see why unplugging the injection pump would do this. I have been fitting P-Boxes for years on these engines and have never had this happen.

Been playining with the reach/rake on car but no joy, is def something to do with me playing with the ecu or battery, all the connectors are firmly in place and no bent pins etc....... the immobiliser is definately cutting the car out, my old a4 did it intermitantly but this is jst refusing to even intermitant the prob, it jst outright runs and cuts out!!!!

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Originally Posted by Crasher

The first thing you need to do is find some way of getting the ECU read for fault codes. Did you disconnect the battery when fitting the tuning box? The immobiliser coding is between the ECU and the instruments, I can't see why unplugging the injection pump would do this. I have been fitting P-Boxes for years on these engines and have never had this happen.

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Hi crasher, thankyou for looking at this you've helped me before on other posts, yes the battery was on off about four times, got the car booked into audi on thurs, its all pretty tricky as its not my car.....

Do you know anyone with VAG-COM?

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Originally Posted by Crasher

Do you know anyone with VAG-COM?

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yeah i do my mates got vag com, but says he thinks its the immobiliser, i dont know how reluctant he would be to come down!!!1

If it is the immob, he could re match it if he has a registered copy. How far away is he?

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Originally Posted by Crasher

If it is the immob, he could re match it if he has a registered copy. How far away is he?

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he lives in the same village but bein the day and time of the year, its a bit tricky!!! is it possible that i have damaged his pump at all? i'm terrified of is as i know how much £ is involved with, is the immobiliser on the pump, i guess the only real way of knowing is diagnostics, prob jst have to wait till thurs!!:(

I didn't want to tell you this but I have seen a pump die due to fitting a tuning box. I used to supply Hopa tuning boxes back in the 90's and we supplied one to a diesel specialists in Nottingham for an A4 2.5 V6 TDI and it immediately fried the pump for no good reason. It was a complete *?~@!£% nightmare as the car was nearly new and getting Hopa to deal with it nearly made me go grey. It was never established what caused it; it had never happened before or since and is one of those periods in life I have tried to forget about.

Quote:

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Originally Posted by Crasher

I didn't want to tell you this but I have seen a pump die due to fitting a tuning box. I used to supply Hopa tuning boxes back in the 90's and we supplied one to a diesel specialists in Nottingham for an A4 2.5 V6 TDI and it immediately fried the pump for no good reason. It was a complete *?~@!£% nightmare as the car was nearly new and getting Hopa to deal with it nearly made me go grey. It was never established what caused it; it had never happened before or since and is one of those periods in life I have tried to forget about.

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This is not good, if this is the case theres no way am goin to be able to fund a new pump for this guy, its mad because we jst drove the car back in the drive removed the box plugged everthing back in and reconnected the battery, he jst check to see if it would start before goin for a coffee, and said fault occured!!! if audi cant find anything with the immobiliser am screwed because when my a4 broke down when i had it they all jst gathered round shaking their heads saying, "what eng code, afb def inj pump" that'll be about £2200 to fix, but turned out to be a low level sender, the car basically ran out of fuel!! i really dont have a good feeling bout this!!

You have got to get a fault code read done today or this is going to ruin New Years Eve for you, it may just be a silly fault. I wish I could be of more help.

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Originally Posted by Crasher

You have got to get a fault code read done today or this is going to ruin New Years Eve for you, it may just be a silly fault. I wish I could be of more help.

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You've been more than helpful as usual crasher:beerchug:!!!!! auch i'll jst have to chill out with a few beers, and forget about this guys car....... until i look out the window and promptly light a small camp fire underneath it,:biglaugh: thank you for the help its great to bend the ear of people who knows there stuff and maybe learn a bit more along the way, ie, leave the spanner work to the daredevils!!!

HAPPY NEW YEAR folks will let y'all know the craic with the car next year!!!

Good luck.

hi folks, jst to update on the 2.5 tdi non starting problem, turns out we bent a pin on the ecu when we were trying to reconnect the ecu multi-plug, so it jst goes to show that you really have to be careful on refitting any electrical connections, a lesson learned!!! thankyou to all who replyed an helped with thier experiences and suggestions..:notworthy

I am really pleased it was that simple.

It looks as if my earlier diagnosis was correct. If something stops working after disturbing connectors then I would always examine the connectors very very carefully before jumping to conclusions. Its happened to me so many times and usually when I'm in a hurry.

Just this morning the immobiliser is stopping me from startin the car. Two weeks ago i disconnecteds the MAF sensor and reconnected it again, so could even a bad sensor connection set off the immobiliser??

Thanks

Emmett

Get a fault code read done on the engine and immobiliser/dash.

Yeah i can get a fault code read done, but would a faulty connection at the MAF sensor trigger the Immobilser?

I'm just wondering was it anything that i could have done that caused the triggering of the Immobiliser....


Thanks

Emmett

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but would a faulty connection at the MAF sensor trigger the Immobilser

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No, I can't see how it would.

Well once i got home from work it started fine, then tried it again and the immobiliser kicked in. So i followed some advice that i read earlier and released the wheel adjuster latch and gave it a good shake up and down and forwards and backwards, and now she starts fine!:D

So it seems there's a loose connection somewhere in the ignition coil or something. As shaking the steering column is not really a permanent fix, I'll see if the immobiliser kicks in again before opening it up and having a look....

Thanks for the advice, i prefer to try sort things out myself before getting shafted by a dealer

A fault code scan will probably show a reader coil fault.