Inspections
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DEFINITION: Momentary lack of response as the accelerator is pushed down. This condition can occur at any vehicle speed. This condition is usually more pronounced when first trying to make the vehicle move, as from a stop sign. This condition may cause
the engine to stall if severe enough.
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Preliminary
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• | Inspect the engine control system grounds for being clean, tight, and in the correct locations. Refer to
Engine Controls Schematics
. Ensure the resistance between the engine control module (ECM) housing and
the battery negative cable is less than 0.5 ohms. |
• | Verify that the ECM and ECM bracket fasteners are at the correct torque. |
• | Inspect the intake air duct and air cleaner outlet resonator for the following conditions: |
- | Improperly installed hoses |
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Sensor/System
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• | Test the heated oxygen sensors (HO2S). The HO2S should respond quickly to a change in throttle position. If the HO2S does not respond to different throttle positions, inspect for contamination from fuel, silicon, or incorrect use of RTV sealant.
The sensors may have a white powdery coating. The coating causes a low, but false, signal voltage, which gives a rich exhaust indication. The ECM reduces the amount of fuel delivered to the engine, causing a driveability condition. |
• | Inspect the mass air flow (MAF) sensor for the correct operation. Refer to
DTC P0101
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Fuel System
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Ignition System
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• | Inspect for the correct installation of the ignition coil seals. Incorrect installation may allow water to enter the spark plug area. Inspect for moisture and corrosion. |
• | Remove the spark plugs and inspect for the following conditions: |
- | Refer to the following procedures: |
• | If the spark plugs are gas, coolant, or oil fouled, determine the cause before replacing the spark plugs. Refer to the following procedures: |
- | For diagnosis of coolant contaminated spark plugs, refer to
Loss of Coolant
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• | Inspect the crankshaft position (CKP) sensor for the correct resistance. The sensor resistance may be out of range after a hot soak. Measure that the resistance remains within 700-1,200 ohms at all temperatures. |
• | Inspect the spark plug boots and terminals for burning or micro-arcing, corrosion, and damage to the insulation. |
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Engine Cooling System
| Test the engine thermostat for the correct operation and heat range. Refer to
Thermostat Diagnosis
.
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Additional
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• | Inspect for a condition with the camshaft actuator system. A camshaft actuator that is stuck in the full advance or retard position may cause this symptom. Refer to
DTC P0011, P0014, P0021, or P0024
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• | Test the generator output voltage. Refer to
Symptoms - Engine Electrical
. Repair the charging system if the generator output voltage is less than 9 volts or more than 16 volts. |
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