Jetta SDI diesel cars using Bosch's VP37 electronically controlled axial piston pump, by the engine electronic control unit ECU according to the signal sent by each sensor, the logic operation, issued a final execution command, control VP37 axial piston Type fuel injection start time and fuel injection, so that it meets the engine starting, idle, small load, medium load, heavy load, full load and acceleration and other needs of the situation.
    Maintenance personnel received a Jetta SDI diesel car repair, the car configuration AQM engine idle operation is unstable, the process of acceleration and weakness, and the phenomenon of mild smoke. Jetta diesel cars can cause the cause of idling instability, generally caused by the following aspects:
    (1) the cylinder pressure of individual cylinders is too low.
    (2) VP37 axial piston pump is damaged, resulting in uneven fuel supply.
    (3) individual cylinder injectors are damaged or clogged.
    We first tested the cylinder pressure, the cylinder pressure in the standard range (2500 ~ 3100kPa) within. Excluding the cylinder pressure problem, the fault point is concentrated on the VP37 pump and the injector. With V. A. G1551 for testing, test results: ① no fault in the memory. ② diesel fuel injection rate of 2.0mg / s or so changes, a larger range of change. ③ The fueling time starts at 94.