Checking the gap

When measuring the distance it is necessary to be sure that you are at right angles with the flywheel and by a tooth and not a hollow.

Checking the gap

The rpm and TDC sensor is fixed directly to the engine crankcase and therefore no adjustments of the gap or the angular position are required. If a problem is suspected it is possible to check the gap, proceeding as follows:

• remove the rpm and TDC sensor;
• check that the distance between the surface of the sensor and the flywheel tooth corresponds to the sum of the length of the sensor probe (34.5 mm) with the gap (0.8 - 1.5 mm).

DETONATION SENSORS
(0.261.231.095)

The detonation sensors are located in the monobloc below the inlet manifolds and between cylinders 1-2 and 4-5, respectively. These sensors have a bush to prevent incorrect torque wrench tightening. If they are replaced, do not place washers or shims between the engine crankcase and sensor contact surfaces.

When there is engine knocking (detonation) vibrations of a certain frequency are created in the cylinder block/crankcase.

The phenomenon creates mechanical repercussions on a piezoelectric crystal which sends a signal to the control unit which, on the basis of this signal, makes provisions to reduce the ignition advance (from 3° to a maximum of 9.7°) until the phenomenon disappears. Afterwards the advance is gradually restored to the basic value.

Wiring connector

The numbers indicate the corresponding control unit pins.

Recovery

The ignition advance is calculated according to the temperature of the engine coolant and the temperature of the intake air.