Spark Control Relay: Testing and Inspection

Spark Delay Valve, 1977-80, 1980-82 exc. Calif.

1. Remove air cleaner and disconnect vacuum line from distributor.

Fig. 38 - Spark Delay Valve Test:

2. On 1977-78, disconnect vacuum control line at intake manifold fitting and install distributor vacuum line to intake manifold fitting, Fig. 38.

Fig. 39 - Spark Delay Valve Test:

Fig. 40 - Spark Delay Valve Test:

3. On 1979-82, disconnect air bypass line on California models, Figs. 39 and 40, or air anti-afterburn valve on except California models and connect distributor vacuum line disconnected previously to intake manifold fitting.

Fig. 41 - Spark Delay Valve Test:

4. Remove vacuum line from carburetor side of vacuum delay valve, then plug in and connect a vacuum gauge to vacuum delay valve, Figs. 39, 40 and 41.

5. Start engine and allow to idle.

6. Disconnect vacuum line from intake manifold fitting.

NOTE:The time required for vacuum reading to drop to 11.8 inches Hg. If amount of time is not within 4-6 seconds, replace valve.

Spark Delay Valve, 1981-82 2.3L Calif, 1982 2.OL Calif.

Fig. 42 - Spark Delay Valve Test:

1. Disconnect vacuum sensing tube from spark delay valve at distributor solenoid and connect a vacuum gauge to tube.

NOTE: On 1982 vehicles, add a 30mm vacuum reservoir between spark delay valve and vacuum gauge.

2. Disconnect vacuum sensing tube from spark delay valve at distributor vacuum advance unit and connect tube to intake manifold.

3. Start engine and note vacuum reading at idle.

4. Disconnect tube from intake manifold and check time required for vacuum reading to drop decrease by 11.8 inches Hg. vacuum. Time required should be 5 ± 1 seconds.