The Mechanic Online Reference

Apr 19, 2018

List of Car problems and the component that may cause

List of Car problems and the component that may cause


POOR PERFORMANCE

  Component check sequence

  1.     Air intake system/vacuum system - leaks
  2.     Air intake filter
  3.     Electrical connections - engine/battery
  4.     Engine management system - connections/wiring
  5.     Fuel filter/fuel pump (FP)
  6.     Engine coolant temperature (ECT) sensor
  7.     Throttle control unit
  8.     Manifold absolute pressure (MAP) sensor
  9.     Intake air temperature (IAT) sensor
  10.     Fuel pressure/delivery rate
  11.     Injectors
  12.     Heated oxygen sensor (HO2S)
  13.     Engine control module (ECM)



POOR ENGINE RESPONSE

Component check sequence
  1.     Air intake system/vacuum system - leaks
  2.     Intake manifold air control solenoid(s)
  3.     Electrical connections - engine/battery
  4.     Engine management system - connections/wiring
  5.     Throttle control unit
  6.     Engine coolant temperature (ECT) sensor
  7.     Fuel filter/fuel pump (FP)
  8.     Fuel pressure/delivery rate
  9.     Injectors
  10.     Engine control module (ECM)



MISFIRE AT IDLE SPEED

Component check sequence
  1.     Air intake system/vacuum system - leaks
  2.     Intake manifold air control solenoid(s)
  3.     Ignition system
  4.     Engine coolant temperature (ECT) sensor
  5.     Electrical connections - engine/battery
  6.     Engine management system - connections/wiring
  7.     Fuel pressure/delivery rate
  8.     Injectors
  9.     Engine control module (ECM)


MISFIRE AT CONSTANT SPEED

Component check sequence
  1.     Ignition system
  2.     Manifold absolute pressure (MAP) sensor
  3.     Injectors
  4.     Air intake system/vacuum system - leaks
  5.     Intake manifold air control solenoid(s)
  6.     Heated oxygen sensor (HO2S)
  7.     Engine control module (ECM)



KNOCK DURING ACCELERATOR

Component check sequence
  1.     Engine management system - connections/wiring
  2.     Knock sensor(s) (KS)
  3.     Manifold absolute pressure (MAP) sensor
  4.     Engine control module (ECM)



INCORRECT IDLE SPEED

Component check sequence

  1.     Air intake system/vacuum system - leaks
  2.     Evaporative emission (EVAP) canister purge valve
  3.     Intake manifold air control solenoid(s)
  4.     Electrical connections - engine/battery
  5.     Engine management system - connections/wiring
  6.     Throttle control unit
  7.     Injectors



HESITATION WHEN ACCELERATING

 Component check sequence
  1.     Air intake system/vacuum system - leaks
  2.     Intake manifold air control solenoid(s)
  3.     Electrical connections - engine/battery
  4.     Engine management system - connections/wiring
  5.     Engine coolant temperature (ECT) sensor
  6.     Fuel filter/fuel pump (FP)
  7.     Fuel pressure/delivery rate
  8.     Injectors
  9.     Heated oxygen sensor (HO2S)
  10.     Engine control module (ECM)


HESITATION ON OVERRUN

Component check sequence
  1.     Electrical connections - engine/battery
  2.     Engine management system - connections/wiring
  3.     Engine coolant temperature (ECT) sensor
  4.     Fuses/fuel pump (FP) relay/engine control (EC) relay
  5.     Throttle control unit
  6.     Injectors
  7.     Intake manifold air control solenoid(s)
  8.     Air intake filter
  9.     Manifold absolute pressure (MAP) sensor
  10.     Intake air temperature (IAT) sensor
  11.     Engine control module (ECM)

HESITATION ON OVERRUN

Component check sequence
  1.     Air intake system/vacuum system - leaks
  2.     Intake manifold air control solenoid(s)
  3.     Electrical connections - engine/battery
  4.     Engine management system - connections/wiring
  5.     Air intake filter
  6.     Manifold absolute pressure (MAP) sensor
  7.     Intake air temperature (IAT) sensor
  8.     Engine coolant temperature (ECT) sensor
  9.     Fuel filter/fuel pump (FP)
  10.     Fuel pressure/delivery rate
  11.     Injectors
  12.     Engine control module (ECM)



EXCESSIVE FUEL CONSUMPTION

Component check sequence
  1.     Air intake filter
  2.     Engine coolant temperature (ECT) sensor
  3.     Throttle control unit
  4.     Engine management system - connections/wiring
  5.     Manifold absolute pressure (MAP) sensor
  6.     Intake air temperature (IAT) sensor
  7.     Injectors
  8.     Engine control module (ECM)


ERRATIC IDLING

Component check sequence
  1.     Air intake system/vacuum system - leaks
  2.     Evaporative emission (EVAP) canister purge valve
  3.     Intake air temperature (IAT) sensor
  4.     Intake manifold air control solenoid(s)
  5.     Electrical connections - engine/battery
  6.     Engine management system - connections/wiring
  7.     Throttle control unit
  8.     Engine coolant temperature (ECT) sensor
  9.     Fuel pressure/delivery rate
  10.     Injectors
  11.     Engine control module (ECM)
  12.     Manifold absolute pressure (MAP) sensor


ENGINE WILL NOT START

Component check sequence

  1.    Immobilizer
  2.     Inertia fuel shut-off (IFS) switch
  3.     Electrical connections - engine/battery
  4.     Engine management system - connections/wiring
  5.     Fuses/fuel pump (FP) relay/engine control (EC) relay
  6.     Fuel filter/fuel pump (FP)
  7.     Ignition system
  8.     Air intake system/vacuum system - leaks
  9.     Manifold absolute pressure (MAP) sensor
  10.     Injectors
  11.     Fuel pressure/delivery rate
  12.     Engine mechanical condition
  13.     Exhaust system/catalytic converter
  14.     Engine control module (ECM)

ENGINE STARTS THEN STOP

 Component check sequence
  1.     Electrical connections - engine/battery
  2.     Air intake filter
  3.     Air intake system/vacuum system - leaks
  4.     Engine management system - connections/wiring
  5.     Throttle control unit
  6.     Fuel pressure/delivery rate
  7.     Injectors
  8.     Engine control module (ECM)
  9.     Manifold absolute pressure (MAP) sensor

ENGINE DIFFICULT TO START -ENGINE WARM

Component check sequence
  1.     Electrical connections - engine/battery
  2.     Fuel filter/fuel pump (FP)
  3.     Air intake system/vacuum system - leaks
  4.     Evaporative emission (EVAP) canister purge valve
  5.     Intake air temperature (IAT) sensor
  6.     Engine management system - connections/wiring
  7.     Engine coolant temperature (ECT) sensor
  8.     Fuel pressure/delivery rate
  9.     Injectors
  10.     Engine control module (ECM)

ENGINE DIFFICULT TO START -ENGINE COLD

 Component check sequence
  1.     Electrical connections - engine/battery
  2.     Fuses/fuel pump (FP) relay/engine control (EC) relay
  3.     Fuel filter/fuel pump (FP)
  4.     Crankshaft position (CKP) sensor
  5.     Camshaft position (CMP) sensor
  6.     Air intake system/vacuum system - leaks
  7.     Intake air temperature (IAT) sensor
  8.     Engine coolant temperature (ECT) sensor
  9.     Manifold absolute pressure (MAP) sensor
  10.     Fuel pressure/delivery rate
  11.     Injectors
  12.     Throttle control unit
  13.     Engine management system - connections/wiring
  14.     Engine control module (ECM)

CO LEVEL - TOO HIGH

Component check sequence
  1.     Air intake filter
  2.     Heated oxygen sensor (HO2S)
  3.     Throttle control unit
  4.     Engine coolant temperature (ECT) sensor
  5.     Electrical connections - engine/battery
  6.     Engine management system - connections/wiring
  7.     Injectors
  8.     Manifold absolute pressure (MAP) sensor
  9.     Intake air temperature (IAT) sensor
  10.     Evaporative emission (EVAP) canister purge valve
  11.     Engine control module (ECM)

CO LEVEL - TOO LOW

Component check sequence
  1.     Air intake system/vacuum system - leaks
  2.     Heated oxygen sensor (HO2S)
  3.     Air intake filter
  4.     Throttle control unit
  5.     Engine coolant temperature (ECT) sensor
  6.     Fuel filter/fuel pump (FP)
  7.     Fuel pressure/delivery rate
  8.     Injectors
  9.     Manifold absolute pressure (MAP) sensor
  10.     Intake air temperature (IAT) sensor
  11.     Engine management system - connections/wiring
  12.     Engine control module (ECM)