Montero 4WD L4-2555cc 2.6L SOHC (1984)
The dual EGR valve system used on Federal vehicles, consists of primary and secondary EGR valves, Fig. 14. Each valve is controlled by different port
vacuums in response to throttle valve setting. The primary valve controls EGR flow for vehicle operation within a relatively narrow range of low throttle
valve settings. The secondary control valve allows recirculation of exhaust gas when the throttle valve is further open. The vacuum applied to the dual
EGR control valve is controlled by a thermo valve.
Fig. 33 Sub-EGR control valve
EGR flow is suspended at idle by the sub EGR valve, Fig. 33 and at full throttle by the lack of port vacuum.
