Engine shutdown

I have the following problem:

This week while driving in first gear suddenly turns off the engine.
The engine turns off when I open the throttle to 5000rpm and when I close the throttle to 0
It seems to me that the overload?

You know what it might be - a bug in the ECU?

Modifications in SD:
2nd-3rd Gearsesor removal
Installed Memjet
BMC Airfilter
Leovince


Thanks