System Inspection

1. Warm up the engine to normal operating temperature and let it idle.
2. Disconnect the vacuum hose from the MAP sensor solenoid valve side of the manifold absolute pressure sensor.




3. Put a finger on the port of the MAP sensor solenoid valve and verify that no vacuum is felt.




4. Open the throttle valve. Increase the engine speed to 4,000 rpm and hold it.
5. Put a finger on the port of the manifold absolute pressure sensor solenoid valve and verify that vacuum is felt.
6. If not as specified, check following:
- Manifold absolute pressure sensor solenoid valve
- Vacuum hose for damage or looseness
- ECM terminal voltages
3E (Mass air flow sensor)
4P (MAP sensor solenoid valve)
4AH, 4AL (Crankshaft position sensor)
3X (Closed throttle position switch)