S10/T10 P/U 2WD V6-262 4.3L VIN Z TBI (1995)
EGR Valve: Description and Operation
Port EGR Valve
Port EGR Valve
OPERATION
The port Exhaust Gas Recirculation (EGR) valve in this system is operated by vacuum. The vacuum is modulated by the Electronic Vacuum
Regulator Valve (EVRV) solenoid which is actuated by the control module.
This valve is controlled by a flexible diaphragm which is spring loaded to hold the valve closed. Vacuum applied to the top side of the diaphragm
overcomes the spring pressure and opens the valve in the exhaust gas port. This allows exhaust gas to be pulled into the intake manifold and enter
the engine Cylinders.
