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 air flow (MAF) sensor and the throttle body.
• Inspect for air leaks at throttle body mounting area, mass air flow (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