1.8 Tdci Engine Missfire Knocking

[rj55elj]

i have a 2007 1.8 tdci which developed a missfire on motorway i continued to services about 10 mile and had car recovered by rac vospers ford in torquay put the car on a machine which showed no faults they checked the timing and valve clearence settings and did a comppression test which showed no loss of compression but wanted to take the head off to inspect the and see if they could rectify the fault i didnt want that done as i was on holiday and had the car recovered back to wales i have had a mobile mecanic look at the car and after trying a few different things we found that number 1 and 3 injectors were not firering which lead him to belive that there was no power supply to the injectors and thats why it was missfiring and sounded like the cam was knocking has anyone had any problems like this or could give me any advice on a cure for the problem