Trailing

Fig. 15 Trailing Diaphragm.:

NOTE: A/T vehicles should be in gear.
1. Pull off vacuum hose at trailing vacuum advance diaphragm Fig. 15.
2. There should be no vacuum at idle.
3. Raise engine speed.
4. Above 2500 rpm (2900-3100 rpm, 1984-85) vacuum should be present.

Fig. 3 Vacuum routing.:

5. If no vacuum, check for 12 volts at trailing vacuum control solenoid above 2500 rpm (2900-3100 rpm, 1984-85) Fig. 3.
6. If 12 volts is present and there is vacuum to the solenoid valve, replace the solenoid valve.