Tune-up and Engine Performance Checks: Testing and Inspection
ENGINE TUNE-UPEngine Tune-up Preparation
1. Warm up the engine to normal operating temperature.
2. Shift the transaxle into neutral.
3. Turn off all electrical loads.
^ Headlight
^ Blower fan
^ Rear window defroster
^ A/C
4. Verify that the steering wheel is in the straight ahead position.
5. Connect the SST (WDS or equivalent) to the DLC-2.
Ignition Timing Inspection
1. Perform "Engine Tune-up Preparation".
2. Short the DLC terminal TEN to body GND using a jumper wire.
3. Select the IGT PID.
4. Verify that IGT PID within the specification.
Specification:
4 - 16 °BTDC (10 ± 6 °)
5. Increase the engine speed and verify the IGT PID value is advanced.
^ If it is not advanced, inspect the following.
- CKP sensor and related harness.
- MAP sensor and related harness.
Idle Speed Inspection
1. Perform "Engine Tune-up Preparation".
2. Short the DLC terminal TEN to body GND using a jumper wire.
3. Verify that the RPM PID is within the specification.
^ If not as specified with all load conditions, inspect the IAC valve.
^ If not as specified with some load condition, inspect the related input switches, harnesses, and connectors.
Specification:
Load Condition Idle-Up Speed (rpm) *1
No load 650 - 750
E/L ON *2 650 - 750
P/S operating *3 700 - 800
PVC ON *4 670 - 770
*1: Excludes temporary idle speed drop just after the electrical loads (E/L) are turned on.
*2: Headlight is on, Fan switch is above 1st, Cooling fan is operating, Rear window defroster is on.
*3: Steering wheel is fully turned.
*4: A/C switch and fan switch are on.
Idle Mixture Inspection
1. Perform "Engine Tune-up Preparation".
2. Verify that the idle speed and ignition timing are within the specification.
3. Warm up the engine by holding the engine speed at 2,500-3,000 rpm for approx. 3 minutes.
4. Insert an exhaust gas analyzer to the tailpipe.
5. Verify that the CO and HO concentrations are within the specified limits.
^ If not within the specified limits, inspect the following:
- On-board diagnostic system.
- HO2S.
- Intake manifold vacuum.
- Fuel line pressure.
- Ignition timing control.
^ If the systems and devices are normal, replace the TWO.