Visual/Physical Check
Several of the symptom procedures call for a careful visual and physical inspection. This can lead to correcting a condition without further tests and can save valuable time. This inspection should include the following areas:
- Inspect the PCM grounds for being clean, tight, and in their proper location. Refer to Power and Grounding Component Views in Wiring Systems.
- Inspect vacuum hoses for splits, kinks, and proper connections, as shown on Vehicle Emission Control Information label. Inspect thoroughly for any type of leak or restriction.
- Inspect the air intake ducts for being collapsed, damaged areas, looseness, improper installation, or leaking, especially between the Mass Airflow (MAF) sensor and the throttle body.
- Inspect for air leaks at throttle body mounting area, Mass Airflow (MAF) sensor and intake manifold sealing surfaces.
- Inspect the wiring harness for poor connections, pinches, cuts, or other damage.
- Inspect for loose, damaged, or missing sensors and/or components.
Use the following tables when diagnosing a symptom complaint:
- Intermittent Conditions
- 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
- Malfunction Indicator Lamp (MIL) Inoperative
- Malfunction Indicator Lamp (MIL) Always On
- Engine Cranks but Does Not Run