Peugeot Jetforce 50 - Driving Me Nuts!

Hope someone can help me before I either A. Jump up and down on the bloody scooter and go to the pub, or B. Jump up and down on the bloody scooter and go to the pub.......

I've got my son a 2004 Jetforce 50 TSDI fuel-injected 2-stroke for when he's 16. The scooter hasn't run for quite a while and I'm struggling to find much technical info on them so am hoping one of you has some direct experience....

The scooter has a good spark, the compressor is delivering good airflow to the injector unit and I know I've got fuel up to the injector. The plug stays dry though. Clearly it's either wiring or the injector unit itself but I've got no facility to test them. Does anyone have any relevant experience of these horrible little things?!! I don't know why a simple little 50cc engine needs to be so electronically complex.

Thanks for any input and pointers.