Evaporative Emissions System: Testing and Inspection

SYSTEM SERVICE
Ensure all vacuum hoses and electrical wires are routed clear of the exhaust manifold to prevent deterioration due to the high temperature. Vacuum hoses should always be a minimum of three inches from the exhaust manifold. When replacing the charcoal canister, mark then disconnect vacuum hoses from charcoal canister to ensure proper installation.

NOTE: Use only fuel resistant hoses when servicing the evaporative control system.

CHARCOAL CANISTER
The charcoal canister is a sealed service-free unit.

EGR System Testing:

EGR/Canister Purge Solenoid Operation:

SOLENOID TEST
Bring the engine to normal operating temperature. Operate at idle speed. Test the EGR/Evaporative canister purge solenoid as follows:
- Check vacuum at solenoid vacuum source hose. Disconnect the line and attach a vacuum gauge to it.
- Vacuum should be a minimum of 15 inches.
- If vacuum is low, check the lines for kinks, twists, or a loose connection at throttle body vacuum port.
- If vacuum is OK, remove gauge, reconnect the line and proceed to next step.
- Check vacuum at solenoid output port.
- Disconnect the line and attach a vacuum gauge to output port. Vacuum reading should be zero (no vacuum) at this side of solenoid.
- If vacuum reading is zero, leave the gauge connected and proceed to next step. If vacuum is present, check solenoid/ECU operation with the DRB-II Service Diagnostic Tester or equivalent and repair as necessary.
- Disconnect electrical connector at solenoid and note vacuum at solenoid output port. Vacuum should now be present at output port.
- If vacuum is not present, replace the solenoid.