poor start a2 90 bhp tdi

pc759

A2OC Donor
hello
this is what i think has happened and invite comments to say yes or no.
Ive checked through a search for people who have had similar.
Got out of school today the carwas a little reluctant to start (first time ever!)
Never mind i thought, could be pilot error with key i began to question whetehr i'd waited for the light to go off...
I needed fuel so went up the road and put in £20 or approx 15 litres
When i came back: car not starting so i cranked it until it did as i didnt want to be stuck anywhere. At this point my glow plug light started flashing and hasn't gone off and the engine light on the other side is also on permanently. Neither of these were there when starting from outisde work. So i think ive caused a crank speed sensor signal by turning the engine over until it started I will need to get it cleared and see what happens
What do you think?
 
Hi pc759
Poor starting on diesels is often caused by fuel leaks / fuel filter problems causing loss of system prime but this does not normally trigger any warning lamps.
The engine won't start if the crankshaft speed sensor fails but a faulty camshaft position sensor could give the symptoms you describe. Take a note of any fault codes before they are cleared when you have the diagnostic scan.

Cheers Spike
 
hey guess what ??
got in the car this morning and somewhere on the way to work the lights went off of their own accord!!
Interestingarticle on the a8 electronics in car mechanics magazine this motnth BTW whic mentions the camshaft signal sensor etc
well alls well that ends well but i wont hold my breath





Paul
 
Hey guess what? the undiagnosed and ignored gremlin from above has returned...
I have to extend my cranking even when parked on an incline and last service was done by audi so this makes me think that the fuel lines are ok and system is prime manintaining at rest and anyways it drives fine once going ( although on reflection i am a little miffed at recent otherwise unexplainable increase in consumption to a poor 52 mpg).
If it was the crankshaft sensor it probably wouldnt start in anycase at all would it? And i have managed to get it going each time
Glowplugs only 2/3 working? Does anyone know how to check these and i wouldve thought they would last longer than 52k miles . My journeys are 2x 15 miles x 5 days p.w would this cause premature loss of life expectancy?
Any comments gratefully received
BTW went to see frankie boyle last week he was gooood
see laughter lounge for 2 gags bbc wont broadcast
Paul
 
Get a VAG COM scan done by someone who knows what theyre about. Youre also lucky enough to be less than an hour away from Skipton Autos!:D
 
Is Skipton Autos (looked them up on the internet) the place to take your troublesome Tdi for a scan?

Skipton Autos was just a 'Club' nickname for Skipton01, one of the A2oc's founder members, and not an actual garage. He's not been around the Forum for a while but helped out many members in the past.
Whatever you found on the internet won't be linked to him and is unlikely to be a garage specialising in A2s.

Cheers Spike

PS It's always an advantage to be a little more precise with your location rather than just show the county - and may result in someone local offering help
 
Thanks for the tip Spike and the clarity. I did wonder if Skipton Autos was a reference to Skipton 01.

I'm Boroughbridge based and my A2 Tdi has an intermittent starting problem. From cold or when hot it starts instantly. If its part warmed up or partially cooled down it can crank without firing as if it’s starved of fuel. I’ve replaced the crank sensor (details posted elsewhere on A2OC) but this has not resolved to problem. The fuel filter is genuine Audi and the glow plugs were replaced a few months ago.

Any advice appreciated.
 
When did you last change the fuel filter ? I had similar symptoms with my car after a service and the bleed nipple has been over tightened and broken on the plastic fuel filter housing. It's only to be torqued to 2nm so it needed a new part which sorted the problem for me.
 
When did you last change the fuel filter ? I had similar symptoms with my car after a service and the bleed nipple has been over tightened and broken on the plastic fuel filter housing. It's only to be torqued to 2nm so it needed a new part which sorted the problem for me.

Just checked the service book, replaced with a genuine Audi filter April this year. The starting problem has developed more recently. Interestingly there have been no issues this week, it's a very intermittent problem.

I’ll check the filter housing. What would I be looking for, a very slight leak?
 
If you've not noticed a leak it's unlikely to be the filter housing. Mine had a distinct smell of fuel and a weeping leak that left a residue on the ground when parked up. So if that's not present or at least some trace of fuel around the heat shield in front on the nearside rear wheel then I'd be looking elsewhere.
 
There are no leaks on the fuel system, the issue with poor starting is becoming more prevalent and the car has started to misfire.

Starting issues I believe are most commonly caused by fuel leaks (there isn’t one), crank sensor (replaced and ran much better for while), temperature sensor? The starting problem never occurs when the engine is cold; could anybody suggest how to test the temperature sensor?

Misfires I believe are most commonly caused by a faulty air mass meter (last replaced over 100k miles ago) and faulting injector wiring harness (last replaced approximately 40k miles ago)? Anybody able to suggest a course of action or do I need to cycle off and find a garage with a fault code reader? What is the software they need to have?

Thanks
 
Bought a cheap Diagnostic Scanner and software from eBay. The software and installation instructions are rubbish but I managed to find a driver online and download free VCDS - Lite software. I now have a fault code 19463 - Camshaft Position Sensor (G40) : No Signal P3007 - 35 - 10 Intermittent. Searched for a how to thread for guidance without any luck. Is this a big job to replace the sensor?
 
this sound plausible, as the ECU will use the crank sensor as a fall back if the cam sensor fails, however with the cam sensor it knows which cylinder to inject (the crank sensor alone cannot tell as crank does 2 revs per cam single rev)
 
Thanks depronman for the explanation, it’s good to understand why the car was malfunctioning and behaving the way it was.

It’s fixed by the way and fitting the crankshaft sensor is a quick and easy job.
 
Phil/ Paul,
I'd appreciate your thoughts on this - we have had a few intermittent issues of long cranking & no start (maybe 2 or 3 in as many months).
- On one occasion I was able to attach an Autel OBD and check the RPM reading when attempting to start - it stayed at 0rpm
- On a successful start it would be at the usual ~250rpm.
- I'm assuming the RPM comes from the crankshaft sensor. No fault codes stored

On one instance at the weekend past we had long cranking, then the car started but died nearly straight away.
- Waited a few minutes then its started and has been fine this past 2 days.

I did a VCDS scan and got the P3007 camshaft no signal error.

I see you have had similar issues and replaced the crank sensor, then at a later date the camshaft sensor.
- Did your car ever cut out once started?
- I'm really trying to determine if a failed camshaft sensor would cause the car to cut out, or, as I've read - just increase start times due to timing coming from the crank instead.

TBH by the sounds of it I would be as well to replace both crank and camshaft to be sure.
- Did you get the HAAS sensors from eurocarparts for crank and camshaft?
- I can get both for £56.91 at the moment, I must price up TPS.

John
 
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