sounds like the same as mine, it has a weak injector if you turn it off do you have trouble starting it back up? the engine warnig comes up and puts the lorry in safe mode thats why it will not rev high... it's a nightmere i had it happen for two weeks and no body could help me....... was it the wiring, the breaks, the imobilisor,the driver, the fuel, no it was the injector! hope you get it sorted!
Nick
April 2011