Models up to 8/93
Note: in models from 9/93, the increase in the crankshaft speed at idle is carried out by the electronic control unit, so there is no need for manual adjustment. In earlier models, the heating element located in the cylinder head, depending on the coolant temperature, acts through the rod but the fuel injection pump control lever and thus, when the engine is cold, ensures an increase in the crankshaft speed at idle. Thanks to this, the engine reaches its operating temperature faster and its dynamic qualities are improved.
Removal
Loosen the traction nipple fastening - small arrow - and disconnect the drive rod from the control lever.
Unscrew the heating element together with the rod from the cylinder head.
Installation
Install the thermocouple with rod, equipped with a new copper sealing ring, into the cylinder head.
Warm up the engine to operating temperature (the coolant temperature should be approximately +90°C).
Place the control lever in position O, hang the rod and screw on the rod nipple.
Hang the rod on the counter support and use the adjusting bolt and lock nut - large arrow in figure S/23C/32d - to adjust so that there is a gap of approximately 2 mm between the rod nipple and the control lever.