Troubleshooting

5-cylinder engine: cold start valve (2) with connector (1).

The illustration on the right shows the mixture control unit with shut-off valve (1), air bleed nozzle (2), air filter (3), metering distributor (4), pressure regulator (5) and shut-off valve potentiometer (6).

The illustration on the left shows the correct position of the shut-off valve with the air bleed nozzle. It must be exactly a = 1.9 mm below the upper edge of the narrow cylindrical part of the air bleed nozzle. If necessary, correct by carefully bending the spring (shown in the illustration as a "zigzag"). Note: Newer air flow sensors are equipped with an adjusting bolt instead of a spring. In this case, the position of the shut-off valve is adjusted with the said bolt.

The idle speed control valve of the 5-cylinder engine is located at the front right of the cylinder head.

With the intake hose removed, both throttle valves (3 and 4) are visible in the throttle valve housing. The linkage system (2) on top of the housing opens first one and then, as the accelerator pedal is pressed further, the second throttle valve. Item (1) shows the idle switch.

On the front left of the cylinder head, in the coolant connection, are located: the engine coolant temperature sensor for the injection system (1) and the electronic thermal switch (2) for the coolant temperature gauge, coolant warning lamp, air conditioning, etc.

The diagram below shows the resistance of the coolant temperature sensor as a function of temperature.

The following sections describe the troubleshooting procedures that do not require any special tools or measuring instruments. If, after reading our fault list (at the end of the chapter) or after reading the fault memory, you suspect a particular component, you will find the test procedure here.