For 1990-2009 cars

#### Lack of Power, Sluggish or Spongy Symptom

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
Definition: The engine delivers less than the expected power. There is little or no increase in the speed when the accelerator pedal is pushed down part way.
1 | Did you perform the On-Board Diagnostic (OBD) System Check? | -- | Go to Step 2 | Go to the Powertrain On Board Diagnostic (OBD) System Check
2 |

1. Perform a bulletin search.
2. If a bulletin that addresses the symptom is present, correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom?

--

Go to Step 17

Go to Step 3

3 | Did you perform a visual/physical check? | -- | Go to Step 4 | Go to Symptoms for the Visual /Physical Check
4 |

1. Remove and check the air filter element for dirt or for a restriction.
2. Replace the air filter element if necessary.

Was a repair required?

--

Go to Step 17

Go to Step 5

5 | Check the Intake Plenum Switchover Valve and the Intake Resonance Switchover Valve for a proper operation. Refer to DTC P1112 Intake Plenum Switchover Solenoid Control Circuit and DTC P1113 Intake Resonance Switchover Solenoid Control Circuit . Was a problem found and corrected? | -- | Go to Step 17 | Go to Step 6
6 |

1. Check for low fuel pressure. Refer to Fuel System Diagnosis .
2. If a problem is present, repair as necessary.

Was a problem found?

--

Go to Step 17

Go to Step 7

7 |

1. Use a J 39383-A in order to check for water or alcohol contaminated fuel.
2. If a problem is present, repair as necessary.

Was a problem found?

--

Go to Step 17

Go to Step 8

8 |

1. Use a scan tool in order to monitor the Knock Retard for an excessive spark retard activity.
2. If a problem is present, repair as necessary.

Was a problem found?

--

Go to Step 17

Go to Step 9

9 |

1. Check for a proper ignition coil output voltage with spark tester J 26792 (ST 125) by performing the following procedure:

1.1. | Clip the spark tester J 26792 to engine ground.

1.2. | Connect one end of a spark plug wire to the spark tester J 26792 . Leave the other end of the spark plug wire connected to the coil that is being tested.

1.3. | Disconnect the spark plug wire from the other spark plug on the same coil being tested. Ground the wire.

1.4. | Crank the engine while observing the spark tester J 26792 . Look for a blue spark.

1.5. | Repeat the above steps for each coil.

2. If an adequate spark is not present at all of the coils, repair as necessary.

Was a problem found?

--

Go to Step 17

Go to Step 10

10 |

1. Remove the spark plugs. Check for the following conditions:

• | Wet plugs

• | Cracks

• | Excessive wear

• | An improper gap

• | Burned electrodes

• | Carbon tracking on the insulator

• | Heavy deposits. Refer to Ignition System Check .

Notice: Determine the cause of the oil or gas fouled spark plugs in order to avoid damage to the new spark plugs.

2. If a problem is present, repair as necessary.

Was a problem found?

--

Go to Step 17

Go to Step 11

11 |

1. Check the ignition coils for cracks or carbon tracking.
2. If a problem is present, repair as necessary.

Was a problem found?

--

Go to Step 17

Go to Step 12

12 |

1. Check the ECMPCM grounds for being clean, tight and in the proper locations.
2. If a problem is present, repair as necessary.

Was a problem found?

--

Go to Step 17

Go to Step 13

13 |

1. Check the exhaust system for a possible restriction:

• | Inspect the exhaust system for any damaged or collapsed pipes.

• | Inspect the muffler for heat distress or a possible internal failure.

• | Check for a possible plugged catalytic converter by checking the exhaust system back pressure. Refer to Restricted Exhaust System Check

2. If a problem is present, repair as necessary.

Was a problem found?

--

Go to Step 17

Go to Step 14

14 |

1. Check the Torque Converter Clutch (TCC) for a proper operation. Refer to Transmission Diagnosis
2. If a problem is present, repair as necessary.

Was a problem found?

--

Go to Step 17

Go to Step 15

15 |

1. Check for the following Engine Mechanical problems. Refer to Engine Mechanical:

• | Low compression

• | Sticking valves

• | A hydraulic valve lifter problem

• | Leaking cylinder head gaskets

• | Worn or incorrect camshaft

• | Incorrect cam timing

• | A damaged timing belt

2. If a problem is present, repair as necessary.

Was a problem found?

--

Go to Step 17

Go to Step 16

16 |

1. Review all of the diagnostic procedures within this table.
2. When all of the procedures have been completed and no malfunctions are present, review/inspect the following items:

• | The scan tool data

• | The Freeze Frame data

• | All of the connections within a suspected circuit and/or system

3. If a problem is present, repair as necessary.

Was a problem found?

--

Go to Step 17

Go to Step 3

17 | Operate the vehicle under the same conditions (as closely as possible) as when the original symptom occurred. Is the original symptom still present? | -- | Go to Step 3 | The repair is complete. If another driveability symptom exists, refer to Symptoms .