Location of the plug in the ignition timing adjustment socket on 260 models in the position for operation on 95-octane unleaded gasoline
Location of the plug in the ignition timing adjustment socket on 300 models in the position for operation on 95-octane unleaded gasoline
EZL Ignition System
The EZL ignition system operates based on the signal received from the crankshaft angle sensor. The ignition system sets the required ignition timing based on engine speed, crankshaft position and manifold vacuum information received from sensors installed on the engine.
A distinctive feature of the EZL ignition system is that it is impossible to adjust the initial ignition timing by turning the distributor housing relative to the shaft.
However, the initial ignition advance angle can be changed depending on the type of fuel used. To do this, it is necessary to change the position of the switching plug in the adjustment socket, located in the engine compartment next to the ECU. The switching plug contains resistors of different resistance. The plug can be installed in several positions in accordance with the marks on the plug. Depending on which resistor of the plug is currently connected to the socket contacts, the ECU of the ignition system increases or decreases the initial ignition advance angle in 3° increments.
The ignition timing angle can also be measured using a stroboscope.
Caution! The ignition timing must be checked with the engine warmed up to normal operating temperature. It is advisable to complete the ignition timing check before the coolant temperature exceeds 95°C or before the radiator fan turns on.
1. Connect the stroboscope in accordance with its operating instructions. In this case, the stroboscope should be started from the high-voltage wire of the 1st cylinder.
2. Run the engine at idle speed. Point the strobe light at the pointer on the timing chain cover. The mark on the crankshaft pulley appears to be stationary and should be aligned with the pointer. If the mark moves to one side or the other, the idle speed is unstable. When checking the ignition timing, all electrical consumers should be switched off and the radiator fan should not be running. When idling for some time, even with the engine warmed up to normal operating temperature, especially at high outside temperatures, the idle speed may be unstable.
3. Determine the ignition timing angle using the mark on the crankshaft pulley, aligned with the pointer.
4. If the ignition timing angle differs by more than 3° from the required value, the plug in the adjustment socket may not be installed correctly. Check the position of the plug in the adjustment socket and, if necessary, install it in accordance with the type of fuel used.