
Volkswagen Golf/Jetta 2 manual
Automatic air cleaner temperature control - testingFuel and exhaust systems - carburettor models / Automatic air cleaner temperature control - testing
1 Unclip and remove the vacuum unit and inlet pipe but leave the vacuum pipe connected (see illustration).
4.1 Air cleaner vacuum unit
2 Suspend a thermometer in the flow of air through the inlet duct then start the engine.
Between -20°C and + 20°C, the control flap in the unit should be a maximum of 2/3rds open to admit hot air from the exhaust manifold.
Above 20°C, the control flap must close the hot air supply (see illustration).
4.2 Air cleaner load and temperature control diagram – 1.05 and 1.3 litre
A Temperature regulator B Intake pipe with thermostat C Vacuum unit
3 The control flap movement can be checked by sucking on the vacuum inlet.
4 With the engine running and inlet air temperature above 20°C, disconnect the vacuum hose from the vacuum unit. The control flap should fully open within a maximum of 20 seconds.
5 If the control unit does not operate correctly then renew it, together with the temperature sensor (see illustration).
4.5 Upper view of air temperature sensor - 1.3 litre
6 Refit the vacuum unit and inlet pipe.







