300SD (126.120) L5-3.0L DSL Turbo (617.951) (1982)
Idle Speed: Adjustments
Checking Maximum Speed at No-Load
CHECKING MAXIMUM SPEED AT NO-LOAD
Test value
Maximum speed at no-load (end of control range): 4900-5200 rpm
Tools: Digital tester e.g. Bosch, MOT 001.03
Checking
1. Connect digital tester to diagnosis socket.
2. Run engine to 60-80 °C coolant temperature.
3. Slowly accelerate to full throttle at accelerator pedal and read revolution counter. Engine speed should attain 4900-5200 rpm.
4. If engine fails to reach specified speed, check whether pressure applied to vacuum control unit at injection pump is negative or not,
disconnecting hose from control unit for this purpose. If engine still fails to reach specified speed, remove injection pump and adjust maximum
speed at no-load on a Bosch injection pump test bench.