Visual/Physical Inspection

Several of the symptom procedures call for a careful visual/physical check. The importance of this step cannot be stressed strongly enough. This step can lead to correcting a problem without further checks and can save valuable time. This check should include:

• ECM grounds for the following conditions:
  • Clean connection
  • Tight connection
  • Proper location

    Refer to Power and Grounding Component Views in Wiring Systems.

• Vacuum hoses for the following conditions:
  • Splits
  • Kinks
  • Proper connections as shown on Vehicle Emission Control Information label-Refer to Evaporative Emissions (EVAP) Hose Routing Diagram .
  • Leaks
  • Restrictions
• Air leaks at the following components:
  • Throttle body mounting
  • Intake manifold sealing surfaces
• Wiring for the following conditions:
  • Proper locations
  • Pinches
  • Cuts
• Use the following tables when diagnosing a symptom complaint:
  • 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