Blazer 4WD V8-350 5.7L VIN L 4-bbl (1982)
EGR Control Solenoid: Description and Operation
Some engines are equipped with an EGR bleed solenoid located in the EGR line.
Engine Cold
The bleed solenoid--energized when the engine is cold--bleeds off system vacuum so the EGR valve will operate at half normal vacuum.
Engine Warm
Solenoid is de-energized allowing full ported vacuum to be applied to the EGR valve.
Torque Converter Clutch Engaged
Some bleed solenoids reduce vacuum to the EGR valve when the torque converter clutch is applied.