You used a "shot gun" approach to fixing your car. Let me explain ; Your
assumption the injectors were the culprit with bad car performance was either
based on 2nd hand advice or your past experience... add to that the fact you
bought used injectors leaves you no guarantee they are any better than the ones
you changed.
Does the car have high mileage (over 120Km) , has it overheated, has the car
been well maintained and have you changed the filters (I'm assuming your car is a
diesel) ?
You may still have dirty injectors and or a coked up turbo, try some tank additive
and go for a nice 50 mile run where you can maintain 70 mph .
