2011 e70 40d stalled,crank no start

[donnynelson]

so the full story
car had DPF.EGR and swirl flap delete done and mapped
also at same time timing chain changed.
ran spot on no issues.
1 week later and +500miles covered
driving as normal stopped behind traffic moved on stopped again but the car just stalled ,restarted but just stalled again instantly.
could not move it and would not start but cranked no problem.
AA came out and diagnosed no pressure to fuel rail it only showed 3 bar.
no codes apart from lin bus due to deletes.
transported to mechanic
fuel tank pump changed.
started,stalled
secondary pump changed and connecting pipes as one was split
no start.
high pressure fuel pump taken off and had (silver death) metal wear residue
reconditioned fuel pump put on
car started for 30 seconds then stalled again
mechanic blanked all sensors etc and tested pressure it had full pressure then drops after 30 seconds .
he is stummped he does not know why it keeps dropping pressure.
my inital thoughts were fuel pump sensor, fuel pressure sensor or crank shaft sensor but mechanic dismissed theses as no codes show.
has any one else had this and sorted the problem.
also the machanic has had the car over 8 weeks now aswell.
cheers

[gotboostedvr6]

What’s your rail pressure?

[donnynelson]

went back up over 600 but then after 30 seconds dropped out and stalled. possibly return valve according to mechanic

[donnynelson]

just to update
after all the parts were changed turns out when the car had all the deletes and the mapping done the ecu reset and then did the emergency 500 mile shut down. been remapped and ecu coded to my chassis , running ok at the minute