1.9 AWX stalling on idle

[mrnice]

2001 avant 1.9tdi 130 awx 176k

Hello folks, a problem introduced itself today-

Driving on motorway after a day out mostly at motorway cruising speeds, down off-ramp and engine cut out as soon as i dropped the clutch.
Managed to start it after waiting a bit and some time of pumping accelerator. Since then it won't idle at all without me feathering the acc pedal (I mean not in the least- just stops dead), and wont start unless I leave it to cool for some time.
Once moving car drives as normal (turbo boost fine, no limp mode or power loss or anything).

Nursed it home, vcds (lite) scan threw up no faults.
All gauges normal (battery fine, coolant at 90 etc).

Started straight up when left to cool down for an hour or so (temp gauge at 60).
The idle definitely seems rough and fluctuating but haven't tried driving it since getting back.

So basically-
Hot starting issue and won't idle when hot,
Starts but idles rough when cold.

Any advice would be greatly appreciated as usual,

cheers

[a8 tech]

look at fuel pressure and look at the crank/cam signals firstly

seems like the cam sender with the warm start but again pressure pre tandem is one to look at and cam signal for quick start recognition

if the cam signal drops the crank will substitute but you will find the starting is longer, if the crank signal fails it will cut out

check the amperage at the fuel pressure pump as well

[mrnice]

Thanks, that all makes sense to me in theory but checking these things is way beyond my limited experience.
Was optimistically hoping for some magic dodgy sensor fix as can be common in modern cars but I may be off
to my local independent garage with this one....

[mrnice]

Actually found a few threads suggesting relay 109 as a possible cause..,
will report back any progress...

[mrnice]

Update-
so I used the car today- 4 different drives on motorway, B roads and in town, hasn't stalled on idle again at all but is randomly difficult to start unkess left for a few minutes (10mins or so). Oddly the car is actually feeling smoother than normal and returned better than usual mpg on motorway.

ps, it seems more likely to give trouble starting after a proper blast at fast motorway speeds..

[mrnice]

A quick update on this, the car appears to have fixed itself. A week or two of daily use and it's been totally fine.
i imagine some bad fuel or something could the cause.