Navajo 4WD V6-4.0L OHV (1991)
Early Fuel Evaporation ( EFE ): Testing and Inspection
VACUUM OPERATED HEAT CONTROL VALVE
Vacuum Operated Heat Control Valve
1.
Connect a hand vacuum pump to the vacuum motor of the Heat Control Valve.
2.
Apply and trap 10-15" vacuum (33.77-67.54 kPa).
3.
The valve must close and lose no more than 2" vacuum (6.75 kPa) in 60 seconds.
4.
When vacuum is released, the valve must open.
If results differ from above, replace the HCV.
BIMETAL HEAT CONTROL VALVE
Bi-metal Spring Heat Control Valve
1.
Visually inspect the heat control valve for any abnormal conditions.
2.
Check the valve and thermostatic spring operation by manually rotating the valve shaft.
Valve must move freely and return to the closed position when the spring is cold.
3.
Lubricate the valve and shaft with graphite lubricant or equivalent.
