Fast Idle THERMO Valve
- Remove intake air duct from throttle body. Start engine. Place finger over port inside throttle body. See Fig 1. With coolant temperature less than 86°F (30°C) and engine at idle, vacuum should be present at port in throttle body. If vacuum is not present, replace fast idle thermo valve and recheck for symptom.
- Warm engine to operating temperature. Check for absence of vacuum at throttle body port. If any vacuum is felt, valve is leaking. Check coolant level. If okay, replace fast idle thermo valve.
NOTE:
For Idle Air Control (IAC) valve information and test procedures, see TESTS W/CODES
article.