Evaporative Emissions System: Testing and Inspection

VAPOR CANISTER

Results From Incorrect Operation
Poor idle, stalling and poor driveability can be caused by:
- Damaged canister.
- Hoses split, cracked and or, not connected to the proper tubes.

Evidence of fuel loss or fuel vapor odor can be caused by:
- Liquid fuel leaking from the fuel lines.
- Cracked or damaged vapor canister.
- Disconnected, misrouted, kinked, deteriorated or damaged vapor pipe, or canister hoses.
- Air cleaner or air cleaner gaskets improperly seated.

Visual Check Of Vapor Canister
- Replace vapor canister if cracked or damaged.
- Replace vapor canister if fuel is leaking from bottom and check operation of the entire system.

THERMOSTATIC VACUUM SWITCH
With the engine coolant temperature below 38°C (100°F), apply vacuum to the manifold side of the switch. Switch should hold a vacuum.
Raise the temperature of the engine to above 50°C (122°F). Vacuum should drop off.
If valve fails either test, Replace it.