Hi everyone

Just looking for some ideas to why my car keeps cutting out

So right after winter storage, at first start it sat idling for some minutes and suddenly just cut out. and kept cutting out when retrying.
A lot of testing and fault finding later and still no joy. although it has now developed so that it cuts out after 10 seconds - very constant
So I start the car and its starts just fine, runs fine, and then 8-10 sec later it seems to go lean, and just cuts out - the change from running fine to cuttig out happens very quickly. it begins to run lumpy for mayby 1-2 seconds and then it cuts out.

I have tried running the pump from another electrical source and it behaves excactly the same. Tried different pump, and also briefly without the fuel filter. Have tried blowing compressed air through the fuel hoses and it seems to be fine although I could be tempted to give it another go. because new fuel reg installed (went from adjustable to 3.5bar weber) and the fuel pressure is now 2,3 when the pump is priming - was 3bar before with adjustable reg. but it still behaves the same.

No sensor faults detected by IAW software

Have checked for vacuum leaks, but no luck (by pressing the throttle it just cuts out a little quicker, - had there been a leak I would have expected to be able to keep it running by pressing throttle)

I have changed
Fuel pump
Fuel reg
CPS
MAP sensor
imobilizer removed
relays for ecu and fuelpump changed

beginning to think it could be the ECU - but again it seems perfect looking at he IAW monitor on all sensors

grateful for any ideas