Audi A3 2.0 TDI Starts and runs for 5 mins then cuts out!

[Mongoose]

Hello guys, hope someone is able to shed some light on this for me! 

Fired up my girlfriends a3 the other day after it had been sat for a week, it started and ran for perhaps 30 seconds, engine ran sweet, then the engine died. Tried to start the car again, it ran for only a couple of seconds then cut out again. At first i thought it may be the immobilizer, so i went and got the other key to try but there was no difference. tried disconnecting the battery for 10 mins but still the same. Plugged in an obd reader, and there were no faults found.

Next day i go to start the car again and it fires up and idles for around 5 mins, i give it a bit of throttle and it revs up nicely and sounds fine then the revs drop and it cuts out, try to start again and get the same issue (only running for a few seconds at a time or barely even starting).

Im guessing then by this it must be a fuel supply issue? Worth noting that if i leave the car for a day and come back to it, it will start and run on idle for a few minutes.

In tank pump is priming when key is turned, and i have changed the fuel filter in the engine bay (which was very dirty imo) 

my only other thought is that it could be the high pressure pump in the engine bay? however i do not want to commit to changing it until im a little more sure that that is indeed the issue.

Anybody experienced this before?  

[cliffcoggin]

George.

Did it run well prior to the week of inactivity? If so perhaps the weather is relevant and water has got into the tank. I suggest you open the fuel line in the engine bay and bleed some fuel into a glass jar watching for any water, dirt, rust, or air as a first step. Check the fuel filter again.

[coupe4]

i had very similar problems on a golf gti a few years ago,tried everything, fuel pump,relays,and loads other parts,eventually i had the emmobiliser bypassed and it cured it straight away.greg

[Mongoose]

15 hours ago, cliffcoggin said:

George.

Did it run well prior to the week of inactivity? If so perhaps the weather is relevant and water has got into the tank. I suggest you open the fuel line in the engine bay and bleed some fuel into a glass jar watching for any water, dirt, rust, or air as a first step. Check the fuel filter again.

Yes it was running fine before this happened, maybe a slight rough idle when first started from cold if im being picky, but considering the state of the fuel filter i took out of it i wouldnt be surprised. 
 

Thanks for the advice, i will check this tonight and report back. 
 

Thanks 

[Mongoose]

13 hours ago, coupe4 said:

i had very similar problems on a golf gti a few years ago,tried everything, fuel pump,relays,and loads other parts,eventually i had the emmobiliser bypassed and it cured it straight away.greg

Interesting! I assumed that if immobilizer was the issue it would simply not start at all? 
 

Hoe does one bypass the immobiliser? 
 

Thanks 

[coupe4]

hi,id say an auto electrician would sort it for you

[Mongoose]

Sit rep. 

Hooked the car up to my truck this evening to get it started as the battery was flat, left the car running for around 5 mins then gave it throttle at 2k rpm for another 4-5 mins until the car got warm, and as i suspected a fuel issue, I was confused when the car didnt die? 

All this time the car is still hooked up to the jump leads on my truck. So i take off the jump leads and let the car run, within 1-2 mins of me taking off the jump leads the car dies.

So now i suspect it is the alternator as the car had a new battery in December. Would a failed alternator cause this?

Also i had an ESP error on the dash this evening which has not happened before, and i have no idea if that could be linked, and after the car cut out there was a red battery light on the dash, although it might just be displayed anyway? 

 

Will either get the alternator tested tomorrow or ill buy a new alternator and belt as the car has been sluggish at starting for some time which is why the battery was replaced to begin with.

 

Thanks   

[cliffcoggin]

It's a pity you did not mention December's battery problem when I asked yesterday about how well the car had been running, because defective batteries are known to cause just this sort of electrical problem. It's precisely why I asked the question.

I suggest you possibly now have another faulty battery to replace as well as whatever work is necessary to cure the charging problem.

[Mongoose]

7 hours ago, cliffcoggin said:

It's a pity you did not mention December's battery problem when I asked yesterday about how well the car had been running, because defective batteries are known to cause just this sort of electrical problem. It's precisely why I asked the question.

I suggest you possibly now have another faulty battery to replace as well as whatever work is necessary to cure the charging problem.

To be honest i didnt think it was worth mentioning as it wasnt as if the battery was completely dead it was simply a little more sluggish than usual upon startup if it had been left over the weekend. 
 

usually from past experience with other vehicles a battery is all that is needed and it seemed to cure the sluggishness so i ruled it out. 

i will let you know weather the alternator fixes my issue. 
 

Thanks