1.6 tdi long crank on cold engine

[radiator]

have recentlly noticed, that when my golf mk7 2014 1.6 tdi 105 bhp is cold or left for couple of hours either outside or in my garage, it starts after about 3-4 seconds. Either its is plus 5 celcius or plus 15 celciu makes no difference. No error codes on vcds. Battery is 7 years old but checked under load and still fine. But when I try to start it up after hour or 4 from stoping it starts without any long crank. In a nutshel, first start is a bit longer but every next just after turning my key fires it up without any deley. No idea where to look for the problem. I don't want to replace any part on spec.
In addition, when I attached multimeter to my battery during cranking voltage on battery dropped to 11V than raised to 14,45 for a few seconds just to drop down only to 12.22 and stayed at 12.22 to 12.35 (engine working all the time). Is alternator voltage regulated by ecu?

can turning of start/stop by voltage have an effect on the problem?

 

[DivineChaos]

You letting the plugs cycle? Last Time fuel filter was changed?

 

[radiator]

Fuel filter was changed 200km back with full timing belt kit. When I turn the key needle test ends, glow plugs indicator turns off now start the engine.

 

[Nuje]

My 2.0L Mk7 TDI has sporadically started doing this too. First start of the day - super fast; stop after 3hrs of freeway driving and go to start it again - cranks for 3-5sec. Drive another hour. Stop. Starts right away.
I've decided to just let it be until it becomes persistent and / or a non-start issue.

 

[radiator]

My 2.0L Mk7 TDI has sporadically started doing this too. First start of the day - super fast; stop after 3hrs of freeway driving and go to start it again - cranks for 3-5sec. Drive another hour. Stop. Starts right away.
I've decided to just let it be until it becomes persistent and / or a non-start issue.

Do you have vcds access? Or anyone with the cable? I have recently done fuel pump test 5 times (5 statups after test completed) and now long crank so far. I read somewhere that after fuel filter replacement this job should be done so that let the air way out. I will let you know if the problem is gone in a few days.

 

[radiator]

Below You have my fuel system scanned in vcds.

Looking at the videos can You tell is there is sth wron with my fuell system/pressure or look futher for more issues?

 

[radiator]

I was lucky to have vcds and long crank alltogether. Look plz at video below.
Do you have any ideas why there is that annoying long crank.?