Intermittent start

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TFinn22

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Hello everyone, new to the forum but been searching high and low for a fix to my a3 but nothing seems to pinpoint the exact issue.

I have a 04 plate 2litre tdi A3 and it has been having problems starting for a few months.

What i have to do is put the key in the ignition barrel untill i hear a 'ooooppp' sound and then the digital trip computer tells me I have e.g 350 miles left in the tank. Otherwise it says 0 miles and will not start but will crank, assuming its not the starter motor. When it states a number on the mpg or tank it starts first time so it seems only an elecrical fault.

I have brought a new ignition barrel as seen some of you on this forum that has worked however ive heard it could be the VDS/relay or the instrument panel?

When i talk to my local mechanics they tell me that the vagcom wont connect, but does when the car starts but no faults. They really are confused about it and seem what to replace everything until its fixed.

The analog gauges work fine, and doesnt seem to make any difference if car is hot or cold, tank is full or nearly empty.

Sorry for the long first comment, but it seems to be getting worse and ive been going round in circles looking online and talking to mechanics locally.
 
20190103 162949 20190103 162546
 
Be a bit costly but I would nip it along to my Audi dealership and ask if you can talk to an Master tech explaining the problem and he might be able to give you a clue where to look , either that or someone who knows electric's and vcd's
 
When the car won’t start does the radiator cooling fans kick in when the ignitions left on for about 10 / 15 seconds, also when it wont start does the engine management light not come on at all when the ignition is switched on but the glow plug light stays on all the time ?
 
Jimbo.King said:
When the car won’t start does the radiator cooling fans kick in when the ignitions left on for about 10 / 15 seconds, also when it wont start does the engine management light not come on at all when the ignition is switched on but the glow plug light stays on all the time ?
Click to expand...
Yeah sometimes the fans go on like you said..

Glow plug and engine management light goes off too when it fires up (when digital readout displays a digit)

Its current in a garage at the moment and they are a little perplexed with what it is, he has rang a few people and they seem to thing its to do with the clocks..bizarre i know, however my clock had randomly reset a few times and my battery is fully charged etc.

Lets wait and see..
 
I had the exact same problem and had to key the ignition on / off a few times until the engine management light came on and then it would start, only problem is it kept taking longer and longer each time until it packed up all together.

Vagcom was able to read the engine ECU but only the top half of the vagcom screen would read (vag number , component etc) but you couldn’t read the faults, code it etc.

After 2 days of going through everything to to bottom, inside and out I decided to get a second hand ECU off eBay, I had the part number l needed from vagcom and got one for £20.

With mine totally giving up I was hoping that when fitting the 2nd hand ecu on the car I was looking for the engine management light to come on when the ignition was switched on, it did and started straight away for a few seconds before the immobiliser kicked in and stopped again.

Now knowing it was definitely the ECU at fault I needed the immobiliser side of it sorting, I found company’s the would remove the immobiliser all together but that would then cause me other problems like it saying SAFE all the time above the speedo reading and the electric windows won’t work + the car wouldn’t have an immobiliser.

I ended up taking both ECU’s to a company called pro remaps in Huddersfield, he read the immobiliser chip off the original ECU and programmed the 2nd hand ECU immobiliser. Everything works spot on and had no problems at all in the last 4 months.

I suppose any remap company that has the equipment to programme the EDC16 ECU would be able to programme the immobiliser side of it for you if you get a second hand ECU, I got charged £35 to have it done.
 
Jimbo.King said:
I had the exact same problem and had to key the ignition on / off a few times until the engine management light came on and then it would start, only problem is it kept taking longer and longer each time until it packed up all together.

Vagcom was able to read the engine ECU but only the top half of the vagcom screen would read (vag number , component etc) but you couldn’t read the faults, code it etc.

After 2 days of going through everything to to bottom, inside and out I decided to get a second hand ECU off eBay, I had the part number l needed from vagcom and got one for £20.

With mine totally giving up I was hoping that when fitting the 2nd hand ecu on the car I was looking for the engine management light to come on when the ignition was switched on, it did and started straight away for a few seconds before the immobiliser kicked in and stopped again.

Now knowing it was definitely the ECU at fault I needed the immobiliser side of it sorting, I found company’s the would remove the immobiliser all together but that would then cause me other problems like it saying SAFE all the time above the speedo reading and the electric windows won’t work + the car wouldn’t have an immobiliser.

I ended up taking both ECU’s to a company called pro remaps in Huddersfield, he read the immobiliser chip off the original ECU and programmed the 2nd hand ECU immobiliser. Everything works spot on and had no problems at all in the last 4 months.

I suppose any remap company that has the equipment to programme the EDC16 ECU would be able to programme the immobiliser side of it for you if you get a second hand ECU, I got charged £35 to have it done.
Click to expand...

That sounds exactly like the problem.. thanks for the detailed reply, really helpfull!
 
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Jimbo.King said:
I had the exact same problem and had to key the ignition on / off a few times until the engine management light came on and then it would start, only problem is it kept taking longer and longer each time until it packed up all together.

Vagcom was able to read the engine ECU but only the top half of the vagcom screen would read (vag number , component etc) but you couldn’t read the faults, code it etc.

After 2 days of going through everything to to bottom, inside and out I decided to get a second hand ECU off eBay, I had the part number l needed from vagcom and got one for £20.

With mine totally giving up I was hoping that when fitting the 2nd hand ecu on the car I was looking for the engine management light to come on when the ignition was switched on, it did and started straight away for a few seconds before the immobiliser kicked in and stopped again.

Now knowing it was definitely the ECU at fault I needed the immobiliser side of it sorting, I found company’s the would remove the immobiliser all together but that would then cause me other problems like it saying SAFE all the time above the speedo reading and the electric windows won’t work + the car wouldn’t have an immobiliser.

I ended up taking both ECU’s to a company called pro remaps in Huddersfield, he read the immobiliser chip off the original ECU and programmed the 2nd hand ECU immobiliser. Everything works spot on and had no problems at all in the last 4 months.

I suppose any remap company that has the equipment to programme the EDC16 ECU would be able to programme the immobiliser side of it for you if you get a second hand ECU, I got charged £35 to have it done.
Click to expand...

Just an update, had the clocks back and there's no faults on the clocks and next step would be getting an ECU and finding someone with the equipment.. my garage doesnt have that equipment is there anyone in the West Midlands (Wolverhampton) area that can replace ECUs ?
 
Just about to order a 2nd hand ECU to be programmed, rang a few remappers and most are qouting me their standard price of £150 ex vat (£180 total)
 
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