Visual/Physical Check

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:

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

    Refer to POWER AND GROUNDING COMPONENT VIEWS .

• Vacuum hoses for the following conditions:
  • Splits
  • Kinks
  • Proper connections as shown on the Vehicle Emission Control Information label-Refer to EMISSION 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