Ignition Base Timing

Run engine until coolant temperature is 167-194°F (75-90°C). Turn ignition off. Disconnect coolant temperature sensor connector. See Fig 2 . Connect a 320-ohm resistor between coolant temperature sensor connector terminals No. 1 and 3. See Fig 1 .
Disconnect the intake air temperature sensor connector. See Fig 2 . Start engine. Check ignition timing. Refer to the IGNITION TIMING table below in this article.

Fig 1: Coolant Temperature Sensor Connector Terminal I.D.

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Fig 2: Locating Coolant & Intake Air Temp. Sensor Connectors

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

IGNITION TIMING - DEGREES BTDC @ RPM

Application	Specification
With Vacuum	8-12 @ Idle; 39-43 @ 3200 RPM
Without Vacuum	8-12 @ Idle; 22-26 @ 3200 RPM