Intake Air Bypass Control Valve
NOTE:
May also be referred to as Fuel Injection Air (FIA) control system.
NOTE:
Engine coolant temperature must be less than 104°F (40°C).
- Start engine and let idle. Disconnect vacuum hose from intake air pipe. Connect vacuum gauge to disconnected hose. Increase and decrease RPM. Ensure vacuum reading changes as RPM changes. If vacuum reading does not change, check for following:
- Misrouted, leaking, broken or clogged Intake Air Bypass (IAB) system vacuum lines.
- Cracked or defective IAB control valve.
- Increase and hold RPM at 3000 RPM with no load (transmission in park or neutral) until radiator fan comes on, then let idle. Increase and decrease RPM. Ensure vacuum reading does not change with RPM. If vacuum reading changes, check for following:
- Misrouted, broken or clogged Intake Air Bypass (IAB) system vacuum lines.
- Cracked or defective IAB control valve.