Pickup 4WD L4-2559cc 2.6L SOHC (4ZE1) (1988)
EVAP Canister Vacuum Switching Valve: Description and Operation
Canister Vacuum Switching Valve
The ECM controlled canister purge vacuum switching valve (VSV) is in the vacuum line to the purge control valve. Normally closed, the VSV opens
when energized by the ECM. During idle or cold operation, the VSV is closed (de-energized), preventing canister purging. The ECM energizes the
VSV to permit canister purge only under these conditions:
1.
Engine at operating temperature.
2.
Engine must run for a specified length of time.
3.
Vehicle must be operating above a specified road speed.
4.
Throttle must be open more than a specified angle.