Evaporative Emissions System: Testing and Inspection

Purge Control System Test:

PURGE CONTROL SYSTEM TEST


COLD ENGINE TEST - Coolant temperature below 60°C (140°F)
1. Disconnect the air purge hose from the air intake hose and plug the air intake hose.
2. Connect a hand vacuum pump to the air purge hose.
3. With the engine idling, apply 14.8 in.Hg vacuum.
Vacuum should not leak.
4. Increase the RPM to 3000, apply 14.8 in.Hg vacuum.
Vacuum should not leak.

WARM ENGINE TEST - Coolant temperature above 70°C (158°F)
1. Disconnect the red striped vacuum hose from the throttle body and connect it to a hand vacuum pump.
2. Plug the nipple from which the hose was removed.
3. Increase RPM to 3000 within three minutes of engine start-up. Try applying vacuum.
Vacuum should leak.
4. Decrease engine RPM to idle, apply 14.8 in.Hg vacuum.
Vacuum should not leak.
5. Increase RPM to 3000 after three minutes have elapsed from engine start-up. Apply 14.8 in.Hg vacuum.
Vacuum will be maintained momentarily, after which it will leak.




PURGE CONTROL SOLENOID VALVE

NOTE: When disconnecting the vacuum hoses, make an identifying mark on them to ensure proper routing when reconnecting.

1. Disconnect the vacuum hoses (non-stripe and red stripe) from the solenoid valve.
2. Disconnect the electrical harness connector from the solenoid valve.

Purge Control Solenoid Valve Vacuum Test:

3. Connect a hand vacuum pump to the red striped hose nipple.
4. Connect jumper wire leads to the purge control solenoid terminals.
5. Apply a vacuum to the solenoid valve. Vacuum should leak.

Purge Control Solenoid Valve Voltage Test:

6. Apply vacuum while applying voltage directly to solenoid.
Vacuum should not leak.

Purge Control Solenoid Valve Resistance Check:

7. Measure the resistance between the terminals of the solenoid valve. Refer to SPECIFICATIONS.

Purge Control Valve Test:

PURGE CONTROL VALVE

1. Remove the Purge Control Valve.
2. Lightly blow air into canister side nipple. Air should not pass through.
3. Connect a vacuum pump to the vacuum nipple of the purge control valve.
4. Apply 8.0 in.Hg vacuum and lightly blow air into valve from canister side. Air should pass through.

Purge Control Valve Test:

5. Connect the vacuum pump to the positive pressure nipple of the purge control valve.
6. Apply 15.7 in.Hg vacuum. Air should not pass through from canister side of valve.

Two-Way Check Valve Test:

TWO-WAY CHECK VALVE

1. Remove two-way check valve from vapor line.
2. Lightly blow air into each side of valve.
If air passes through after a slight resistance, the valve is good.