Wagoneer L6-258 4.2L VIN C 2-bbl (1982)
Spark Control System: Testing and Inspection
Coolant Temperature Override (CTO) Valve
Standard Cooling
1. Connect a suitable vacuum gauge to center port (port D) of CTO valve.
2. Manifold vacuum should be indicated on gauge when coolant temperature is below 160° F on 1978-79, 149° F on 1980-81, or 155° F on 1982
vehicles. Above this temperature, carburetor ported vacuum should be indicated. If defective, replace valve.
NOTE: Ported vacuum is only available when the throttle is opened to obtain an engine speed of approximately 1000 RPM.
Heavy Duty Cooling
1. Connect a suitable vacuum gauge to port D (Dist.) of CTO valve.
2. When coolant temperature is below 220° F, carburetor ported vacuum should he indicated on gauge. When temperature exceeds 220° F, manifold
vacuum should be indicated. If defective, replace valve.
