Ignition System: Service and Repair
Thermo Vacuum Valve
1. Using suitable vinyl tubes, connect onto EGR and distributor outlet ports.
2. Plug air cleaner outlet port.
3. Blow air into the thermo vacuum valve, and ensure valve opens and closes to the flowing temperatures:
a. The thermo vacuum valve should be open above 68° F, (20° C).
b. The thermo vacuum valve should close below 50° F, (10° C).
c. If valve does not operate within the specified temperatures, replace thermo vacuum valve.