Motor failure

I have a Kia Frontier 2.5 year 2008,
it has 110,000 kilometers,
my consulate is:
The Ralenty truck fails and smoke boot with a smell of fuel (oil) and the engine works uncontrolled this in high revolutions does not do so and does not boot smoke.

I have two other trucks of them and change the injectors with which you have problems and continue with the same symptoms and it was scanned and throws an oxygen sensor that goes to the multiple of admission with problems but changes it and has the same failure.

I want to know if it is the injection pump or some other problem.