GT TDI Intermittent start, now not starting

[ian24driver]

The car wouldn't start yesterday at Sainsburys but the Mrs managed to get it going after a few goes. I've been out in it today without any problems. Just been out but the golf wont start now, at the turn of the key the fuel pump primes as it normally does and the glow plug light comes on and goes off within a second. Not sure how long the glow plug light normally comes on for so not sure if this is normal. It turns over and then dies.

Never had a problem with it so need to know what basics to check.
Thanks. 

[ian24driver]

RAC have come out and the following was on his screen.

Fault code 17965 Charge/pressure control positive deviation (intermittent).

Suspect internal fault with turbo/sensor/boost pressure regulator.

Look like its going in for a visit at my local garage to be sorted. Am I right in thinking it could be one of a few things, RAC man was too specific.

[ian24driver]

After a few days in the garage its had a new starter motor, crank sensor, coolant sensor and some Forte diesel treatment and Forte turbo cleaner.

Ran great for a few days, starts on the button, having ran the treatment through the system and most of the built up crap now gone. Turbo sounds better and the drive is excellent, No limp mode.

Randomly decided not to start after picking up some milk from the shop last night, its a 2 minute drive away from my house so the car would still be cold. I rolled it forward and bump started it and made it home. This morning it started fine, 5 hours later it starts fine again. It seems a bit like Russian roulette as to when this will happen again. Had the battery tested today, all fine. Any ideas folks?

[itavaltalainen]

Sounds like garage had a field day 

The fault code you posted on a first glance should not have anything to do with the parts changed.

Did they look at turbo and rather it's controls?

[ian24driver]

Didn't start this morning....

The mechanic is a friend and has years of vw/audi knowledge so I never doubt his diagnosis. Personally the limp mode business happened months ago before the starting problem the other week so could be related or not.

The forte treatment has made it run much better over the last week and the turbo sounds good, along with performance.

Bit of a head scratcher.

[ian24driver]

I have noticed the anti shudder valve not always opening when turning the engine over. Am I right thinking this could be the problem, with it being so hit and miss as to when it starts or not. Also, once it starts to fail will it generally deteriorate or is there any way to free it up or just buy a new one?

[AntGTD]

Take the ASV and EGR off and using a can of carb clean remove as much of the gunk as gunk as possible. Might be so gummed up that it's not allowing the valve to open or it could be completely blocked.

[ian24driver]

Will attempt that later when I get a spare hour.
 

[ian24driver]

 Anti Stutter Valve  was the problem, was sticking closed once out of 30 attempts at turning over. A good clean when I get a spare hour without the kids.