For 1990-2009 cars

Inspections | Action
--- | ---
DEFINITION: The engine delivers less than expected power. Little increase in speed, or a total lack of acceleration when the accelerator pedal is pushed down part way.
Preliminary Inspections |

• | Refer to Important Preliminary Inspections before starting in Symptoms - Engine Controls .

• | Search for bulletins.

• | 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.

• | Remove the air filter element and inspect for restrictions. Refer to Air Cleaner Element Replacement .

• | Inspect the intake air duct and air cleaner outlet resonator for the following conditions:

- | Restrictions

- | Improperly installed hoses

- | Leaks

- | Collapsed hoses

Fuel System |

• | Test for incorrect fuel system pressure. Refer to Fuel System Diagnosis .

• | Test for a restricted fuel filter. Refer to Fuel System Diagnosis .

• | Test for a contaminated fuel condition. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .

• | Test the fuel injectors. Refer to Fuel Injector Solenoid Coil Test .

• | Test the items that cause an engine to run rich. For a rich condition, refer to DTC P2178 or P2180 and DTC P2188 or P2190 .

• | Test the items that can cause an engine to run lean. For a lean condition, refer to DTC P2177 or P2179 and DTC P2187 or P2189 .

Sensor/System | Monitor the knock sensor (KS) system for excessive spark retard activity with a scan tool. Refer to Knock Sensor (KS) System Description , DTC P0327 or P0332 , and DTC P0328 or P0333 .
Ignition System |

• | 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.

• | Test for the correct ignition voltage output with a J 26792 Spark Tester. If you suspect an ignition system condition exists, refer to Electronic Ignition (EI) System Diagnosis .

• | Remove the spark plugs and inspect for the following conditions:

- | Incorrect heat range

- | Wet plugs

- | Cracks

- | Wear

- | Improper gap

- | Burned electrodes

- | Heavy deposits

- | Refer to the following procedures:

• | Spark Plug Replacement

• | Ignition System Specifications

• | Spark Plug Inspection

• | If the spark plugs are gas, coolant, or oil fouled, determine the cause before replacing the spark plugs. Refer to the following procedures:

- | Test the items that cause an engine to run rich. For a rich condition, refer to DTC P2178 or P2180 and DTC P2188 or P2190 .

- | For diagnosis of coolant contaminated spark plugs, refer to Loss of Coolant .

- | For diagnosis of oil fouled spark plugs, refer to Oil Consumption Diagnosis .

• | 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.

Engine Mechanical |

• | 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 .

• | Inspect for the following engine mechanical conditions:

- | Excessive oil in combustion chamber or leaking valve seals

- | Incorrect cylinder compression

- | Sticking or leaking valves

- | Worn camshaft lobes

- | Camshaft timing

- | Broken valve springs

- | Excessive carbon buildup in the combustion chambers--Clean the chambers with top engine cleaner. Follow the instructions on the can.

- | For more information, refer to the following procedures:

• | Oil Consumption Diagnosis

• | Engine Compression Test

• | Camshaft Timing Drive Chain Alignment Diagram

• | Setting Camshaft Timing

• | Symptoms - Engine Mechanical

• | Inspect the following components for incorrect basic engine parts:

- | Camshafts

- | Cylinder heads

- | Pistons, connecting rods, or bearings

- | Refer to the following procedures:

• | Camshaft Timing Drive Components Cleaning and Inspection

• | Camshaft Cleaning and Inspection

• | Cylinder Head Cleaning and Inspection

• | Piston, Connecting Rod, and Bearing Cleaning and Inspection

Additional |

• | Inspect the following exhaust system components:

- | The exhaust system for damage

- | The mufflers for heat distress or possible internal failure

- | The catalytic converters for restrictions

- | For more information, refer to Symptoms - Engine Exhaust .

• | Test for the correct operation of the intake manifold runner control solenoid. Refer to Intake Manifold Runner Control System Diagnosis .

• | Test the transmission torque converter clutch (TCC) for the correct operation. Refer to Torque Converter Diagnosis .

• | Test for other transmission related faults that might cause the transmission to operate in a default mode.