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 the heated oxygen sensors (HO2S). The HO2S should respond quickly
to different throttle positions. If they do not, inspect the HO2S for silicon or other
contaminates from fuel or the use of improper RTV sealant. The sensors may have a
white, powdery coating and result in a high but false signal voltage rich exhaust
indication. The ECM will then reduce the amount of fuel delivered to the engine
causing a severe driveability problem. |
• | Inspect for proper operation of the throttle position (TP) sensor.
Refer to
DTC P0106
. |
|
Fuel System
|
• | Verify that each injector harness is connected to the correct injector
or cylinder. Relocate the 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 |
- | An evaporative emission (EVAP) canister purge condition |
- | 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. |
- | 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: |
• | Remove spark plugs and inspect for the following: |
- | Verify that the spark plugs are of the correct type. |
• | Inspect for proper ignition voltage output with the J 26792
Spark Tester. |
• | An improper spark plug gap will cause a driveability condition. Gap the
spark plugs using a wire gage gap tool. |
• | Determine the cause of the fouling before replacing the spark plugs. |
• | Inspect for damaged or misaligned spark plug boots. |
• | Inspect the electronic ignition (EI) module for 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
. |
|
Engine Mechanical
| Inspect for excessive crankshaft endplay that will cause the crankshaft position
(CKP) sensor reluctor wheel to move out of alignment with the CKP sensor. Refer to
Crankshaft and Bearing Cleaning and Inspection
in Engine Mechanical - 2.2L. This could result in any of the following conditions:
|
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 transmission torque converter clutch (TCC) for proper
operation. Refer to
Torque Converter Diagnosis
in Automatic Transaxle - 4T40-E/4T45-E. |
• | Inspect the exhaust system for possible restrictions. Refer to
Restricted Exhaust
in Engine Exhaust. |
|