K 2500 Suburban 4WD V8-454 7.4L VIN N TBI (1995)
Canister Purge Solenoid: Description and Operation
The EVAP system in some applications uses an electrically controlled solenoid to cycle the vacuum to the EVAP canister. The control module cycles the
solenoid when engine coolant temperature is > 45°C or the short term fuel trim cell is less than 122 counts. In other applications a vacuum line from a
port vacuum source on the TBI unit works on a vacuum control valve - which cycles open and closed with port vacuum signal.
