#### INSPECTION AND ADJUSTMENTS

Normally the Spark Timing Control systems should be trouble-free. However, if you suspect a problem in the system, first check to make sure all wiring (if so equipped) and hoses are connected and free from dirt. Also check to make sure the distributor vacuum advance is working properly. If everything appears all right, connect a timing light to the engine and make sure the initial timing is correct.

To test the Spark Timing Control System, connect a timing light and check the ignition timing while the temperature gauge is in the cold position. Write down the reading. Allow the engine to run with the timing light attached until the temperature needle reaches the center of the gauge. As the engine is warming up, check with the timing light to make sure the ignition timing retards. When the temperature needle is in the middle of the gauge, the ignition timing should advance from its previous position. If the ignition timing does not change, replace the thermal vacuum valve.

Fig. 1: Spark timing control system — CA20E engine

Fig. 2: Coolant water heated fuel heater — CA20 engine