Just had a look at this, the eu2 engine should run grouped/batched injection, so 1&4 will share the same injector driver and 2&3 will share the other injector driver as far as I can see. If you have a wiring diagram I'll be able to confirm this? i.e There should be the same pulse width for injectors 1 and 4, so if there was a driver failure in the ECU, I'd expect the issue with no 1 to be replicated in no 4...... All things bringing equal I'd have to with the fault with the engine, but I hope that I'm wrong and the new ECU cures the fault...... Meant to ask if there is any smoke form the exhaust, if it was a sticky oil control ring on piston no 1 I'd expect some smoke from the exhaust?