Component Tests and General Diagnostics
1. Disconnect the vacuum hose (green striped) from the exhaust gas recirculation (EGR) valve, and then connect a hand vacuum pump via the three-way terminal.
2. Regarding the engine in cold and hot conditions, check the condition of vacuum when a rapid racing has been performed by opening the throttle valve quickly.
When engine is cold [Engine coolant temperature: 20°C (68°F) or less]
Throttle valve Normal vacuum condition
Open quickly No vacuum will generate (remained as barometric pressure).
When engine is hot [Engine coolant temperature: 70°C (158°F) or higher]
Throttle valve Normal vacuum condition
Open quickly It will momentarily rise over 100 mmHg (3.9 in.Hg).
3. Disconnect the three-way terminal.
4. Connect the hand vacuum pump directly to the exhaust gas recirculation (EGR) valve.
5. Check whether the engine stalls or the idling is unstable when a vacuum of 200 mmHg (7.9 in.Hg) or higher is applied during idling.