Hello everyone, I have own this Mercedes V-Class W638 for some time; but, in recent months, it has been experiencing sporadic starting issues that no garage has been able to solve.
 
	Commence in the mornings It never fails me; nevertheless, after a brief drive and subsequent parking for a while, when I return to start it again... It turns over but fails to ignite. After waiting around thirty minutes and attempting again, it starts immediately.
 
	I have replaced the O-rings on the fuel pressure regulator. 
	The crankshaft position sensor 
	Fuel filtration device 
	O-rings on high-pressure gasoline pump 
	I replaced the injectors and cam sensor a few years ago, so I doubt the cam sensor could have malfunctioned that soon.
 
	Has anybody else encountered this? 
	I would appreciate any guidance you could provide. 
	Thank you