T6 Won't start

[YellowT6Guy]

Greetings everyone
I have a yellow EX AA T6 2litre 6 speed manual which ever since it's turned cold has an intermittent starting issue.

From cold if I go to crank it, it will just turn over and over sometimes it'll sound like it's trying to start other times it just turns over and over but then sometimes it will fire straight up and run absolutely sweet.

Unfortunately I don't have access to VCDS which I think may aid me further

Cam and crank sensor working and in sync virtually figure wise
All fuses have been checked
All earthing points have been thoroughly cleaned same with earth leads

I'm off down into the E Hub today to check glow plug wiring to see if I'm getting voltage there as it's definitely temperature related.

A few months ago I replaced the following parts as they where needed, new yuasa EFB battery, X3 glow plugs except the pressure sensor one as no where had one in stock, timing belt & water pump, full service kit.

Recently I've replaced fuel temp sensor, wiring where it usually breaks not far from the sensor and new plug all from TPS.
Had to re-do the timing belt and water pump due to a leaking water pump 400 miles after it was done
New starter motor yesterday as the old one was a bit sluggish at turning over.

Can anyone offer any aid at all, I am a technician by trade however this one is stumping me massively and I really need my van back! Any helps would be very much appreciated

Regards, Levi.

 

[DaveD]

Greetings everyone
I have a yellow EX AA T6 2litre 6 speed manual which ever since it's turned cold has an intermittent starting issue.

From cold if I go to crank it, it will just turn over and over sometimes it'll sound like it's trying to start other times it just turns over and over but then sometimes it will fire straight up and run absolutely sweet.

Unfortunately I don't have access to VCDS which I think may aid me further

Cam and crank sensor working and in sync virtually figure wise
All fuses have been checked
All earthing points have been thoroughly cleaned same with earth leads

I'm off down into the E Hub today to check glow plug wiring to see if I'm getting voltage there as it's definitely temperature related.

A few months ago I replaced the following parts as they where needed, new yuasa EFB battery, X3 glow plugs except the pressure sensor one as no where had one in stock, timing belt & water pump, full service kit.

Recently I've replaced fuel temp sensor, wiring where it usually breaks not far from the sensor and new plug all from TPS.
Had to re-do the timing belt and water pump due to a leaking water pump 400 miles after it was done
New starter motor yesterday as the old one was a bit sluggish at turning over.

Can anyone offer any aid at all, I am a technician by trade however this one is stumping me massively and I really need my van back! Any helps would be very much appreciated

Regards, Levi.

Have you browsed through similar threads?

Cold start problem

HI all, I have a 2016 T6 Shutlle 150PS DSG. For the last few months I've been having a problem starting after leaving the vehicle overnight, roughly about 12 hours. I does start eventually but takes around 4/5 turns of the key to take life. Warm starts are fine and it drives as normal. I've...

www.t6forum.com

Possibly low fuel pressure, you've already eliminated many of the possible issues.

Search results for query: low fuel rail pressure

www.t6forum.com

 

[YellowT6Guy]

Have you browsed through similar threads?

Cold start problem

HI all, I have a 2016 T6 Shutlle 150PS DSG. For the last few months I've been having a problem starting after leaving the vehicle overnight, roughly about 12 hours. I does start eventually but takes around 4/5 turns of the key to take life. Warm starts are fine and it drives as normal. I've...

www.t6forum.com

Possibly low fuel pressure, you've already eliminated many of the possible issues.

Search results for query: low fuel rail pressure

www.t6forum.com

I have gone through all threads multiple times to no avail unfortunately, I'm at a serious loss. It is my family and work bus so I really am desperate to resolve the issue.

Common rail pressure sensor 1 bank 1 "commanded" value is 320 bar

Common rail pressure sensor 1 bank 1 "actual" actually fluctuates from 220bar to upwards of 350 bar when attempting to start.

I even pulled the HPFP solonoid to see if it was the dreaded filings in the fuel but it was squeaky clean.

If I squirt brake cleaner a small amount into the intake it'll almost hydrolock itself and give me a flat battery like symptoms with it being very lethargic in turning over try that 4 or 5 times then it'll strike into life and run absolutely brilliantly.

 

[Randolph]

Just to confirm that you are not leaving it running stationary parked on a hill with 25% fuel left in tank.
Mine cut out and wouldn’t start until filling the tank with 10L

 

[YellowT6Guy]

Just to confirm that you are not leaving it running stationary parked on a hill with 25% fuel left in tank.
Mine cut out and wouldn’t start until filling the tank with 10L

I mean I don't have a great deal of fuel in there currently but shouldn't surely make a difference? There is a very slight incline on my driveway but it's very very marginal.

It is left running a fair bit yes but like I say when there van is warm it starts up as it should do, only when it's cold it doesn't start?

 

[Randolph]

Well it is worth putting 15L in and try the starter for 30 second intervals and I think it will start.
Mine stopped when parked on a steep incline while I was waiting for the windows to thaw.

 

[YellowT6Guy]

Well it is worth putting 15L in and try the starter for 30 second intervals and I think it will start.
Mine stopped when parked on a steep incline while I was waiting for the windows to thaw.

It's never done it whilst the van is running though chap, it just won't start when cold sometimes it will sometimes it won't but 95% of the time it won't fire. Soon as the van has been running for a while and has some form of heat it'll fire up and continue to do so there on sometimes a little more prolonged than other but will fire up.

 

[david173]

Sounds daft and im sure you have already, but I assume you have checked the battery? When cold im under the impresssion it draws alot more power to start plus cold batteries dont perform as well. Hence once warm it will turn over much easier?

 

[YellowT6Guy]

Sounds daft and im sure you have already, but I assume you have checked the battery? When cold im under the impresssion it draws alot more power to start plus cold batteries dont perform as well. Hence once warm it will turn over much easier?

Tried 3 different batteries now chap as I was thinking the same thing I bought a brand new yuasa EFB about 2 months ago as the old one was weak.

 

[david173]

Tried 3 different batteries now chap as I was thinking the same thing I bought a brand new yuasa EFB about 2 months ago as the old one was weak.

Wont be that then!

 

[YellowT6Guy]

Anyone with any other input, I'm desperate to resolve this issue I really need my van back I don't mind paying someone to come and have a look with vcds to see if they can find anything! Help!

 

[n10n]

I see you have freezing night temperatures. Daft question but when was the fuel filter last changed? Ice there could restrict the fuel flow - just a guess though as your rail pressures seem decent

 

[YellowT6Guy]

I see you have freezing night temperatures. Daft question but when was the fuel filter last changed? Ice there could restrict the fuel flow - just a guess though as your rail pressures seem decent

Was changed literally about 400 miles ago when I gave it a full service, little bit of an update.

So if I turn the ignition on 6 times after it not firing it'll fire into life and run, tried it multiple times now with the same outcome. Footnote after I'd done that I'd let it run a few minutes went to fire it up straight into life repeated it 5 times with the same outcome of it firing up. Going to leave it to go stone cold again as it's nearly minus figures outside again and try again in an hour or so. It's really is a head scratcher this one and I haven't much hair left!

 

[oldiebut goodie]

Weak lift pump in the fuel tank? Had that on a Fiat Punto, pump was intermittent and wouldn't start, changed pump and all was well again.

 

[YellowT6Guy]

When you diagnostically operate it though it primes as it's meant to, I don't want to just throw the parts cannon at it if it doesn't resolve the issue as genuine parts or OEM parts aren't cheap. Haha

Following on from my post above yours, just gone out to try and fire it up after leaving it nearly an hour and it was a prolonged start of about 7 seconds then fired into life and ran mint. Turned it off tried to fire it up again it just turned over, turned it off tried again it fired up, what am I missing?

 

[DaveD]

Was changed literally about 400 miles ago when I gave it a full service, little bit of an update.

So if I turn the ignition on 6 times after it not firing it'll fire into life and run, tried it multiple times now with the same outcome. Footnote after I'd done that I'd let it run a few minutes went to fire it up straight into life repeated it 5 times with the same outcome of it firing up. Going to leave it to go stone cold again as it's nearly minus figures outside again and try again in an hour or so. It's really is a head scratcher this one and I haven't much hair left!

If you hadn't already changed 3 of the glow plugs already I'd have bet money on that being the problem.
I've never had to touch mine, is it possible to pull them and rig up a wire to see if they get a nice glow on them when you try to start the van?

 

[paddy26]

If you're planning on keeping the van it's worth getting vcds or alternative code/sensor reader.

 

[n10n]

Yeah, get a VCDS, especially if you already have a windows laptop dangling about. It will pay itself back in no time even if it doesn’t end up solving the issue - over the years you will spend many a £ and time with 3rd party diagnostics.

There’s so many possibilities… besides what has been mentioned and checked already maybe a faulty fuel non-return valve by the tank or pressure regulation control valve by the rail could cause something like that. The temperature effect points to ice, faulty temperature sensor or glow plugs though. But as you say, no sense throwing parts blindly in - at this point money is better spent on getting diagnostics at will.

 

[cbr600ski]

My dodgy starting issue on a T5 - exactly the same as you describe - intermittent, gets going eventually but takes a couple of turns and was FAR worse in winter turned out to be (a) worn alternator - needed new brushes, and (b) EGR value carbonisation.

 

[YellowT6Guy]

If you hadn't already changed 3 of the glow plugs already I'd have bet money on that being the problem.
I've never had to touch mine, is it possible to pull them and rig up a wire to see if they get a nice glow on them when you try to start the van?

I've checked diagnostically today to see if the glow plug module is working and it is, stays live for 2.5 seconds when ignition is switched on and I've even back probed the wiring to them in the 14 pin connector in the E Hub under the battery it stays live for 2.5 seconds then it stops and flickers between 0v and 10.9v every second which I found strange? Surely it should be 0V? Or am I over thinking that?

With my original issue being them ridiculously low minus readings in the fuel temp sensor & rad outlet coolant temp sensor, I did a continuity check from the fuel sensor back to ECU and that also checked out. So I am lost on what to do with it.

Definitely planning to keep the van I'm a vag man through and through, where is best to buy VCDS?

Thank you all for the replies, hopefully we can get to the bottom of this bloody van!

Regards, Levi.