The fuel pump is equipped with a boost pressure regulator. The main function of this regulator is to reduce exhaust during acceleration or at low revs and at maximum load. The boost pressure regulator is built into the top of the pump. Figure 25.1 shows the arrangement of the turbocharger with the location of its main components.
25.1 Turbocharger design1. Air filter; 2. Intake air compressor; 3. Turbine drive mechanism (turbocharger); 4. Radiator for cooling the forced air; 5. Intake air main pipelines; 6. Fuel pump with boost pressure regulator; 7. Boost pressure indicator; 8. Oil separator (drain to oil pan)
Problems and causes
A) Loss of power: if the boost pressure is correct, check that the connecting hose between the intake pipe (5) and boost pressure regulator (6) in order. It is also possible that the pump is not supplying enough fuel. Please contact a workshop for troubleshooting.
b) Black exhaust is due to insufficient boost pressure: check intake duct for leaks. An air leak can occur, for example, at the connection of the air filter or charge air cooler. A damaged turbocharger can also raise suspicion.
With) Black exhaust at normal boost pressure indicates high fuel delivery. Check the pump in the workshop.