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, as from a stop. May cause the engine to stall if severe enough.
|
Preliminary
|
| • | Verify that the powertrain control module (PCM) grounds are clean, tight,
and in the proper locations. Refer to
Engine Controls Schematics
. |
|
Sensor/System
| Inspect the manifold absolute pressure (MAP) sensor operation.
|
Fuel System
|
| • | Verify that both fuel injector fuses are not open. An open fuel injector
fuse causes 4 ignition coils and 4 fuel injectors not to operate. Inspect
the ignition coil circuits and the fuel injector circuits for an intermittent short
to ground. Refer to
Circuit Testing
and
Wiring Repairs
in Wiring Systems. Replace the fuse. |
| • | 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 heated oxygen sensor (HO2S) connector |
| - | Engine oil contaminated by fuel |
| - | An evaporative emission (EVAP) canister purge condition |
| - | An inaccurate mass air flow (MAF) sensor |
| - | 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. |
| - | An inaccurate MAF sensor |
| - | Vacuum hoses that are split, kinked, or improperly connected |
|
Ignition System
|
| • | Soak the secondary ignition system with water from a spray bottle. Soaking
the secondary ignition system may help locate damaged or deteriorated components.
Look and listen for arcing or misfiring as you apply water. |
| • | Remove the spark plugs and check for the following: |
Refer to
Spark Plug Inspection
.
| • | An improper spark plug gap will cause a driveability problem. Gap the
spark plugs using a wire gage gap tool. Refer to
Spark Plug Replacement
. |
| • | Determine the cause of the fouling before replacing the spark plugs. |
| • | Monitor the Misfire Current Counters while driving the vehicle in the
conditions that the misfire occurred. If a misfiring cylinder can be located, use
the DTC P0300 table for diagnosis. Refer to
DTC P0300
. |
|
Engine Cooling System
| Inspect the engine thermostat for proper operation and for proper heat range.
Refer to
Thermostat Diagnosis
in Engine Cooling.
|
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. This could result in any of the following conditions:
|
Additional Inspections
| Inspect the generator output voltage. Repair the charging system if the generator
output voltage is less than 9 volts or more than 16 volts.
|
