While performing a back leakage test for a second-generation Bosch CR fuel system, the fuel volume was measured to be above specification from the cylinder head. Technician A says the cause could be a leaking quill tube. Technician B says the cause could be one or more injectors with worn-out ball valve seats. Who is correct?

Question

Quizplus · Accepted Answer

Both Technician A and Technician B are correct. A leaking quill tube can cause excessive back leakage, and worn-out ball valve seats in injectors can also lead to increased fuel volume being returned to the tank.

While Performing a Back Leakage Test for a Second-Generation Bosch