TURBOCHARGER OIL PASSAGE INSPECTION
Engine must be cool. Remove oil return pipe. Verify oil passage in turbocharger or oil return pipe is not blocked with carbonized oil. Replace turbocharger and return pipe if necessary.
AIRFLOW METER/SENSOR INSPECTION
Inspect airflow meter for damage and ensure measuring plate moves smoothly. (Scheme 48) Disconnect airflow meter connector. Move measuring plate and measure resistance between terminals. See AIRFLOW METER TERMINAL RESISTANCE table.
| Terminal Wire Color | Volts - Ignition ON | Volts - Engine Running |
|---|---|---|
| Black/Yellow (Power Supply) | 12 | 12 |
| Green/Orange (Burn-Off) | 0 | 0 |
| Green/Black (Airflow Mass) | 1.0-2.0 | 1.9-5.0 |
| Green/Yellow (Ground) | About 0 | About 0 |
| Black/Orange (Ground) | About 0 | About 0 |
AIRFLOW SENSOR TERMINAL VOLTAGES
| Terminals | Ohms - Fully Closed | Ohms - Fully Open |
|---|---|---|
| E2-Vs | 100-400 | 20-1000 |
| E2-Vc | 100-400 | 100-400 |
| E2-Vb | 200-400 | 200-400 |
| E2-THA | (1) 13,600-18,400 | (1) 13,600-18,400 |
| (2) 2200-2700 | (2) 2200-2700 | |
| (3) 500-700 | (3) 500-700 | |
| E1-Fc | Infinite | 0 |
| (1) Tested at -4°F (-20°C). (2) Tested at 68°F (20°C). (3) Tested at 140°F (60°C). | ||
| (1) | Tested at -4°F (-20°C). |
| (2) | Tested at 68°F (20°C). |
| (3) | Tested at 140°F (60°C). |
AIRFLOW METER TERMINAL RESISTANCE
Scheme 48
Testing
Remove connector from switch. Connect ohmmeter to appropriate switch terminals. (Scheme 49) Continuity should exist with gearshift in Park and Neutral. No continuity should exist in any other ranges. If switch does not perform as indicated, replace switch.
Scheme 49
NEUTRAL SWITCH (M/T) TEST
Remove connector from switch. Connect ohmmeter to switch terminals. Check continuity exists with transmission in Neutral and no continuity exists in other ranges. Replace switch if continuity is not correct.
OXYGEN SENSOR (O2) INSPECTION
- Warm engine to operating temperature. Run engine at fast idle. Disconnect O2 sensor. Connect a high impedance voltmeter between O2 sensor and ground.
- Observe voltmeter while rapidly accelerating and decelerating engine speed. Voltage should be 0.5-1.0 volt while accelerating and 0-0.4 volt while decelerating. If sensor is not operating to specifications, replace O2 sensor. Ensure new oxygen sensor has anti-seize compound applied to threads. Tighten sensor to 21-36 ft. lbs. (29-49 N.m).
POWER STEERING PRESSURE SWITCH TEST
- Remove connector from switch. Connect ohmmeter to switch terminals. Start engine and allow to idle. Turn steering wheel from side to side and note continuity reading.
- Continuity should exist when front wheels are turned. Continuity should not exist when wheels are not turned. Replace switch if continuity is not as indicated.
SYSTEM TEST
Check all connectors and hose routings. Check for cracks, leakage, or restrictions and repair as needed. Start engine and check that diaphragm of EGR control valve does not move while engine is cold. Warm engine up to operating temperature at idle. Accelerate engine and check that diaphragm of EGR control valve moves upward. If no movement is detected, check individual components.
Scheme 50
Scheme 51
SYSTEM INSPECTION
Purge system operation takes place when the following conditions are met. Vehicle is accelerating in gear (off idle), engine is at operating temperature and oxygen sensor is functioning normally. (Scheme 52)
Scheme 52
Warm engine to normal operating temperature and run at idle. Disconnect PCV valve together with vent hose from valve cover. Block PCV valve opening and check for vacuum. If no vacuum is felt, check for collapsed line or blockage. See FUEL EVAPORATION vacuum diagrams for hose routing.