For 1990-2009 cars

### Important Preliminary Inspections Before Starting

Before using this section, perform the Diagnostic System Check - Vehicle and verify all of the following conditions:

• | The engine control module (ECM) and the malfunction indicator lamp (MIL) are operating correctly.

• | There are no DTCs stored.

• | The scan tool data is within the normal operating range. Refer to Scan Tool Data List .

• | Verify the customer concern and locate the correct symptom. Inspect the items indicated under that symptom.

• | Several of the symptom procedures ask for a careful visual/physical inspection. This step is extremely important, and can lead to correcting a condition without further inspections and can save valuable time.

• | If an intermittent condition exists as a start and then a stall, inspect for any DTCs related to the theft deterrent system. Refer to Diagnostic Trouble Code (DTC) List - Vehicle .

• | Verify the proper installation of any of the following non-original equipment accessories:

- | Lights

- | Cellular phone

- | Remote starter system

- | Non-factory installed alarm

1. Use the following tables when diagnosing a symptom concern:

• | Hard Start

• | Surges/Chuggles

• | Lack of Power, Sluggishness, or Sponginess

• | Detonation/Spark Knock

• | Hesitation, Sag, Stumble

• | Cuts Out, Misses

• | Poor Fuel Economy

• | Poor Fuel Fill Quality

• | Rough, Unstable, or Incorrect Idle and Stalling

• | Dieseling, Run-On

• | Backfire

2. If the condition cannot be isolated using the appropriate table, refer to Intermittent Conditions for further diagnosis.