Inspection/Tests
| Action
|
DEFINITION: Momentary lack of response as the accelerator is pushed down. Can
occur at any vehicle speed. Usually more pronounced when first trying to make the
vehicle move from a stop. May cause the engine to stall if severe enough.
|
Preliminary
|
|
Sensor/System
|
Notice: Refer to Silicon Contamination of Heated Oxygen Sensors Notice in the Preface section. - Verify that the engine coolant temperature (ECT) sensor has not shifted in
value. Refer to
Temperature Versus Resistance
.
- With the engine idling at normal operating temperature and all of the
accessories turned OFF, the MAP parameter should be within the specified range. Refer
to
Poor Fuel Fill Quality
. If the MAP parameter
is not within the specified range, replace the MAP sensor. Refer to
Manifold Absolute Pressure Sensor Replacement
.
|
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 |
|
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 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:
|
Engine Cooling System
| Inspect the engine thermostat for proper operation and for correct heat range.
Refer to
Thermostat Diagnosis
in Engine Cooling.
|
