Hot Engine System Test

HOT ENGINE





1. Disconnect the # 19 vacuum hose at the purge control diaphragm valve and connect a vacuum pump/gauge to the hose.
2. Wait for the engine to warm up.

There should be vacuum at idle, once engine is warm.

- If vacuum is available, go on to step 3.
- If no vacuum, disconnect # 18 vacuum hose at the thermovalve A and check for vacuum at the # 18 hose.
- If there is no vacuum, check the routing for the # 18 vacuum hose and repair or replace as necessary.
- If there is vacuum, replace the thermovalve A and retest.

3. Disconnect the vacuum pump/gauge and reconnect hose.
4. Remove fuel filler cap.





5. Remove the canister purge air hose from frame and connect hose to a vacuum gauge as shown.
6. Raise engine speed to 3,500 rpm.

Vacuum should appear on the gauge within 1 minute.

- If vacuum appears on the gauge in 1 minute, remove the gauge and go on to step 8.
- If no vacuum, disconnect the vacuum gauge and reinstall the fuel filler cap.

7. Remove the charcoal canister and check for signs of damage.
If damaged, replace the canister. If OK, go on to step 8.





8. Stop the engine. Disconnect the hose from the canister PCV fitting.
Connect a vacuum pump to the canister PURGE fitting as shown, and apply vacuum.

Vacuum should remain steady.

- If vacuum remains steady, go on to step 7.
- If vacuum drops, replace the canister and retest.

9. Restart the engine. Reconnect the hose to the canister PCV fitting.

PURGE side vacuum should drop to zero.

- If PURGE side vacuum does not drop to zero, replace the canister and retest.
- If PURGE side vacuum drops to zero, connect a vacuum pump to canister the PCV fitting, and apply vacuum.
Vacuum should remain steady.
- If vacuum remains steady, disconnect the vacuum pump. Recheck thermovalve A operation on the previous page.
- If vacuum drops, replace the canister and retest.





10. Connect a vacuum pump to TANK fitting as shown, and apply vacuum.

There should not be any vacuum.

- If no vacuum, reinstall fuel filler cap and canister; test is complete.
- If there is vacuum, replace canister and retest.