Evaporative Emission Control
- Disconnect purge control vacuum hose from throttle body. See Fig 1
. Connect a hand-held vacuum pump to purge control vacuum hose. Plug vacuum nipple on throttle body. Ensure engine is at operating temperature.
- Turn engine off. Start engine and let it idle. Right after starting engine, apply 16 in. Hg vacuum to purge control vacuum hose. Vacuum should be maintained. If vacuum is maintained, go to next step. If vacuum is not maintained, repair evaporative emission system.
- With engine idling at operating temperature for 10 minutes or more, apply 16 in. Hg vacuum to purge control vacuum hose. Vacuum should leak. If vacuum leaks, go to next step. If vacuum does not leak, repair evaporative emission system.
- Remove plug from nipple on throttle body. Connect a hand-held vacuum pump to nipple on throttle body. Start engine. Raise engine speed and observe vacuum gauge. Vacuum should remain constant regardless of engine speed. If vacuum remains constant regardless of engine speed, evaporative emission system is functioning properly. If no vacuum is generated, clean clogged throttle body vacuum port.
Courtesy of CHRYSLER CORP.