Inspection/Tests
| Action
|
DEFINITION: Engine power variation under steady throttle or cruise. Feels like
the vehicle speeds up and slows down with no change in the accelerator pedal position.
|
Preliminary
|
• | Verify the driver understands the operation of the transmission torque
converter clutch (TCC) and A/C compressor operation as explained in the owners manual. |
|
Sensor/System
|
Notice: Refer to Silicon Contamination of Heated Oxygen Sensors Notice in the Preface section.
• | Inspect for proper operation of the manifold absolute pressure (MAP) sensor.
Refer to
DTC P0105
. |
|
Fuel System
|
• | Verify that each fuel injector harness is connected to the correct fuel
injector or cylinder. Relocate the fuel injector harnesses as necessary. |
• | Inspect for the following that may cause the engine to run rich: |
Notice: Refer to Heated Oxygen and Oxygen Sensor Notice in the Preface section. - | Water intrusion in the HO2S connector |
- | Purging of a saturated EVAP canister |
- | Vacuum hoses that are split, kinked, or improperly connected |
- | An air intake duct that is collapsed or restricted |
• | Inspect for the following conditions that may cause the engine to run
lean: |
Notice: Refer to Heated Oxygen and Oxygen Sensor Notice in the Preface section. - | Water intrusion in the HO2S connector |
- | An exhaust leak between the HO2S and the engine--Refer to
Exhaust Leakage
in Engine Exhaust. |
- | Proper MAP sensor operation--Refer to
DTC P0105
. |
- | Vacuum hoses that are split, kinked, or improperly connected |
|
Ignition System
| In order to properly inspect the spark plugs or to correct a condition, refer
to the following procedures:
• | Inspect for proper secondary ignition voltage output with the J 26792
(SA9199Z) Spark Tester. |
• | An improper spark plug gap will cause a driveability condition. Gap the
spark plugs using a wire gage gap tool. |
• | If the spark plugs are found to be fouled, determine the cause before
replacing the spark plugs. |
• | Inspect for damaged or misaligned spark plug boots. |
• | Inspect the electronic ignition (EI ) module for a proper ground connection. |
• | Monitor the Misfire Current Counters while driving the vehicle in the
conditions that the symptom occurred. If a misfiring cylinder can be located, use
the DTC P0300 table for diagnosis. Refer to
DTC P0300
. |
|
Additional Inspections
|
• | Visually and physically inspect vacuum hoses for splits, kinks, and proper
connections and routing as shown on the Vehicle Emission Control Information label. |
• | Inspect the exhaust system for possible restrictions. Refer to
Restricted Exhaust
in Engine Exhaust. |
|