REMOVING AND INSTALLING THROTTLE BYPASS VALVE
Loosen hose clamps (1 and 2) and screws (3).
Pull off plug (4).
Remove throttle bypass valve.
Refer to Group 11 for water-heated throttle
bypass valve.
Loosen hose clamp (2) and pull off air hose for
visual inspection.
Air bore of cold engine (+ 20°C/68°F) should
be half open.

1 Shutoff valve
2 Auxiliary air cross section opening
3 Bimetal with heating coil
The shutoff valve will be half open when engine
temperature is + 20°C (68°F).
The shutoff valve should be fully closed when
engine has operating temperature (oil temperature
about 60°C/140°F).

Check power supply for throttle bypass valve.
Connect Jetronic test lead no. 61 1 440 between
supply wire (1) and voltmeter (2).
Voltage higher than 10.8 V should be shown when
operating the starter.

Check coil of throttle bypass valve.
Connect Jetronic test lead no. 61 1 440 between
throttle bypass valve (1) and ohmmeter (2).
The ohmmeter should show a value which is
greater than "O" and less than "oo" (depending
on temperature). At 20°C (68°F) the meter
will show about 40 ohms.