i hope this all makes sence

for the last couple of days my turbo has started to run on 3 cylinders.
i checked all the plugs and they are all working fine no problem there
with the car running i pulled each lead off one at a time and only number 2 made no difference at all
i then checked for fuel and there was no fuel at the red pipe on the meatering at number 2 unit side so i changed the unit for my friends which works fine on this car,
when on my car the problem is still there no fuel at number too
on the other injectors fuel pisses out but nothing on number 2

please help me