Sometime Motor doesn’t start from first time

[Seat_Leon_18FR_5F]

Hi All,
I've this issue with my seat Leon 2018 FR 1.4 TSI, recently after changing a timing belt and Oil pressure value, the start stop sometimes does not work properly and asks to start the motor manually and after a long trip sometimes the motor start from the second time, I went to a dealer , he didn’t find any error by check it with the computer but he asked me to change the battery and I got a new VARTA AGM battery start stop battery and every after installing the new batter the issue happening again.

I took the car to another dealer and check it and check live data by connecting it to the computer, he said the car is good fuel pressure is ok, temperature is good, oil pressure is ok and he didn’t see any issue and there is no any error code in the memory, no signs on the dashboard

Any idea?

TIA

 

[Walone]

Although probably not related, did you code the battery, or have it coded, after fitting the new battery?

 

[Seat_Leon_18FR_5F]

Although probably not related, did you code the battery, or have it coded, after fitting the new battery?

Yes, The battery was coded by the dealer

 

[Marlowe]

I have exactly the same issue on a 2.0 184ps 2013 TDI (CUPA) Leon. 88k on clock.

No error codes being reported. I've tried 3 softwards and our usual garage is unable to diagnose.

Seems to be getting progressively worse. Warm starts seem the worst but it can be intermittent.

Car has had new fuel filter, battery and seperately had new heater matrix and EGR assembly due the coolant blocked by the usual silicone in coolant issue.

Has anyone any ideas before I try ordering new glowplugs / cranksensor and just replace things until I get lucky?

 

[GlekkeMatrak]

I once read that the variable cam timing system always finds a very "easy" starting position, both on intake and exhaust cam. Possibly after the timing belt replacement, something's now different... Wouldn't know what, how or why though... If it were a sensor, there should be a code, unless of course that it's signal is still within plausible range but "shifted". Anyway, I'm just guessing...