A4 TDi 130 Start Up Problem

[jsnmac]

I have an A4 TDi 130 on an 02 plate. Just recently it has an intermittent problem of starting first time. It usually starts up on the button but every now and then i seem to have to turn it over several times before it starts. It seems for few seconds not to have any fuel being delivered? It drives perfectly and i have had it scanned several times and no fault codes are being logged. Something is definately wrong as it started doing it out of the blue after 2 years of ownership. Any help or advice would be extremely welcome.

[StuPDi]

have you checked the glow-plugs??

next time it fails to start 1st time, boil the kettle and pour hot water all over the engine and see if that makes any difference.

if it goes straight away, you will need to replace 1 or more pre-heater, prob make sense to do all four. you can buy stes in Halfords for relatively cheap money :)

Hope you get it sorted :)

Stu

[jsnmac]

Thanks for the reply. I replaced the glow plugs first and two of them were faulty but his hasn't made any difference. The fault just causes the engine to spin over several times and splutter a little bit before firing up. The car can start five times normally and then suddenly it will play up. Nothing has shown up on the diagnostic scans and no one seems to be able to find anything wrong with it when clearly there is. I was wondering if i had some sort of fuel injection problem?

[Turbokiisseli]

Have you changed the fuel filter recently? I might also be worth it to try some sort of Diesel System cleaner like Sonax, CRC or Forte.

[jsnmac]

I have changed the fuel filter at the same time as the glow plugs. The problem is not as bad as it was and is very intermittent. I will try some Diesel treatment at the weekend and see if that helps. The thing is i can't help thinking that something is wrong and at some point is going to fail on me when i really don't want it to. Like i said, though, all the diagnostics are clear and when running is spot on. Thanks for the reply.

[tyberwan]

Does your problem happen specially in the morning after the car was at rest for the whole night?

Does your car fire up normally then during the day?

Did you notice after how long the car was at rest for this problem to happen?

[jsnmac]

It is very random. It has not done it all week but today it has done it everytime i have started the car. It can do it when it is hot or cold, morning or night. Every garage has said to change the air mass meter which has been tried. I don't know where to go from here really. Thanks for the reply.

[tyberwan]

There may be many answers to this one already in the posted threads:

1. Try switching on the headlights before starting the car. Some A4 have this problem with the switch interfering with the start up of the car

2. Otherwise, does the car produce smoke when it finally starts? Colour of smoke?

3. I had almost a similar problem from different sources which I hope is not your case. I will try send you the threads for this. 1st - my camshaft was worn, so my car had difficulty starting. It had done 148k kms by then. 2nd - A few months after that, I had a faulty injector which was surely leaking diesel in the cylinder, so when I start up the car in the morning or night after a few hours rest, it had difficulty starting (4-5 tries on the ignition) and then it would produce a lot of smoke at start.

4. In both of the above cases, no fault codes were detected at the Audi dealer. How they detected a faulty injector was when they replaced it with a new one, no problem occured after that!!! So I had to bear with an injector change.

Both solutions were costly.

[tyberwan]

Here are the threads...


1. Starting problems

http://www.vwaudiforum.co.uk/forum/showthread.php?t=1522&highlight=tyberwan

2.Camshaft change

http://www.vwaudiforum.co.uk/forum/showthread.php?t=19032&highlight=camshaft+change

3. Starting problems in rainy weather

http://www.vwaudiforum.co.uk/forum/showthread.php?t=31773&highlight=faulty+injector

[micheal balbrig]

Here are the threads...


1. Starting problems

http://www.vwaudiforum.co.uk/forum/showthread.php?t=1522&highlight=tyberwan

2.Camshaft change

http://www.vwaudiforum.co.uk/forum/showthread.php?t=19032&highlight=camshaft+change

3. Starting problems in rainy weather

http://www.vwaudiforum.co.uk/forum/showthread.php?

t=31773&highlight=faulty+injector


Could it be a faulty immobiliser I often see notes

about a problem with the unit on the ign. of A 4s

that cause non start

[jsnmac]

Thanks very much i will try the headlamp trick in a bit. It sound like the exact same problem. I hope it that it doesn't end up being a camshaft. I will give the headlamp trick a go first to see if that works. It may take a while to prove as it doesn't do it on every start. Thanks so much for the threads, very much appreciated.

[a8 tech]

code engine ecu for automatic gearbox and retry as the cranking speed may be to low indictating the starter is defective,if it sorts it then fit new starter and code back to manual.The esp light will come on as you will be altering the drivetrain code.Also consider the tandem pump as the holding pressure may be poor also the lift pump may not be operating which pumps the initial cranking fuel at .50 bar and then the tandem pump sucks it in from crankspeed

[a8 tech]

Ill give you some diy tips while im suffering from a cold and bored.If you fit a section of clear fuelpipe from the filter to the tandem pump you will be able to see if fuel is being drawn/pumped when the fault occurs also check fuel temp and air temp redings they should be similar to the ambiant temp,if the coolant is reading negative then disconnect it and crank the engine to see if she fires up.Camshaft wear could only cause hall sender quick fire recognition to go out of spec or to much free play at the injectors adjustment,which could be checked via a dti gauge or measured alue blocks for fuel balancing/injection rate.Also the fuel lift pump fuse is located drivers side fuse box at the end of the dash,its number 28 i think.You could bridge the fuse when the fault occurs giing the fuel lift pump a direct 12volt feed to pump the fuel if its working as the pd engine will start without the lift pump.The glow plugs arent active unless the outside temp is cold (not got the exact temp to hand)so at the moment there not active and pd units dont really rely on the glow plugs like older diesel engines.

[jsnmac]

Thanks for all the replies but for the moment the headlamp trick seems to be working. I had to go from Norwich to heathrow yesterday and after dropping off my in laws i tried to start the car without the headlamps on and it failed to start. Now usually if it fails to start first time i have to really turn over the engine to get it to fire up on the second attempt. i turned the headlamps on and it went first time-very weird. So at the moment it looks like i need a new headlamp switch.

[tdise]

:beerchug:
Here are the threads...

Thanks to your suggestion re the headlight switch. Tried this and my TDI 130 FIRES UP FIRST TIME EVERYTIME...... DOES IT CAUSE ANY LONG TERM ISSUES , OR DO I NEED TO REPLACE THE SWITCH ???????


1. Starting problems

http://www.vwaudiforum.co.uk/forum/showthread.php?t=1522&highlight=tyberwan

2.Camshaft change

http://www.vwaudiforum.co.uk/forum/showthread.php?t=19032&highlight=camshaft+change

3. Starting problems in rainy weather

http://www.vwaudiforum.co.uk/forum/showthread.php?t=31773&highlight=faulty+injector

[jsnmac]

caused me no issues and i ran it like that for a whole year. I did replace the light switch in the end as i had enough of constanly turning on my lights.

[a8 tech]

I think the false feed from the light switch replaces the x relief relay output which should turn off none essential consumers to deliver maximum cranking voltage
In other words the faulty switch interrupts the input for the x relief relay and by turning the switch on j519 energizes the circuit and allows x relief to operate hence voltage increase for cranking.
Thats my theory anyway