My Volvo V70 2000 (base model, no turbo) won't start.

The original problem happened on the highway. While re-accelerating, everything suddenly stopped to work (low RPM 800-1500, no response from gaz pedal....) Engine stalled, and never restarted since that.

I went to a Volvo dealer and the checked for:
-immo wiring
-antenna ring
-fuel pressure
-spark plugs
and everything was fine.

They finally tried with another ECU (from another car) and the engine tried to start more than what it was doing with original ECU (kind of interupt by immo security, wich was normal).

ECU was therefore their first guess in order to repair my car...that had never start again (even if I tried a lot of time, on neutral, with pedal gas on floor, without it....) since it "stall" on the highway.

Any ideas?

 

Timing, compression, cam sensor.

 

Thanks for your answer!
Is it possible to see physical damage to these elements or do there are some tests I can perform to check these?

Your help is really appreciated!