Inspection/Tests
| Action
|
DEFINITION: Engine delivers less than expected power. Little or no increase
in speed when the accelerator pedal is pushed down part way.
|
Preliminary Inspections
|
|
Fuel System
|
• | 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. |
- | Vacuum hoses that are split, kinked, or improperly connected |
|
Sensor/System
| Monitor the knock sensor (KS) system for excessive spark retard activity with
a scan tool. Refer to
Scan Tool Data List
.
|
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 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 ignition 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
. |
|
Engine Mechanical
|
• | Inspect for incorrect camshaft timing. |
• | Inspect for excessive oil in the combustion chambers and leaking valve
seals. Refer to
Oil Consumption Diagnosis
in
Engine Mechanical. |
• | Inspect for incorrect, worn, or damaged basic engine parts, including
the following: |
• | Inspect for excessive crankshaft endplay that will cause the CKP sensor
reluctor wheel to move out of alignment with the CKP sensor. Refer to
Crankshaft and Bearing Cleaning and Inspection
in Engine
Mechanical. This could result in any of the following conditions: |
|
Additional Inspections
|
• | Inspect the exhaust system for possible restrictions. Refer to
Restricted Exhaust
in Engine Exhaust. |
• | Inspect the exhaust system for damaged or collapsed pipes. |
• | Inspect the mufflers for heat distress or internal failure. |
|