Testing Pneumatic Idle Speed Increase (PLA)

Testing pneumatic Idle speed increase (PLA)

Preceding work: Testing, adjusting idle speed Testing, Adjusting Idle Speed






10 In-line injection pump
10/6 Governor housing
12/3 PLA vacuum unit
61 Restriction with filter
61/1 Restriction with filter, white
61/3 Restriction, orance
84/1 Thermovalve, closes 30°C
019 Vacuum tester
104 Vacuum pump
a Air admission to interior
c Other consumers

Warm engine up to coolant temperature > 40°C.
Connect vacuum tester (019) and test supply vacuum.
Specification: ≥700 mbar.

Test thermovalve for leaks. closes 30°C (64/1)
Test PLA vacuum unit (12/3) for leaks.
Test air admission line (sw) for clear passage.

Test data






Special tool






Note: The PLA vacuum unit (12/3) at the injection pump can only be replaced at a Bosch dealership because the governor has to be disassembled and then set on a Bosch injection pump tester.