List of Car problems and the component that may cause
POOR PERFORMANCE
Component check sequence- Air intake system/vacuum system - leaks
- Air intake filter
- Electrical connections - engine/battery
- Engine management system - connections/wiring
- Fuel filter/fuel pump (FP)
- Engine coolant temperature (ECT) sensor
- Throttle control unit
- Manifold absolute pressure (MAP) sensor
- Intake air temperature (IAT) sensor
- Fuel pressure/delivery rate
- Injectors
- Heated oxygen sensor (HO2S)
- Engine control module (ECM)
POOR ENGINE RESPONSE
Component check sequence
- Air intake system/vacuum system - leaks
- Intake manifold air control solenoid(s)
- Electrical connections - engine/battery
- Engine management system - connections/wiring
- Throttle control unit
- Engine coolant temperature (ECT) sensor
- Fuel filter/fuel pump (FP)
- Fuel pressure/delivery rate
- Injectors
- Engine control module (ECM)
MISFIRE AT IDLE SPEED
Component check sequence
- Air intake system/vacuum system - leaks
- Intake manifold air control solenoid(s)
- Ignition system
- Engine coolant temperature (ECT) sensor
- Electrical connections - engine/battery
- Engine management system - connections/wiring
- Fuel pressure/delivery rate
- Injectors
- Engine control module (ECM)
MISFIRE AT CONSTANT SPEED
Component check sequence
- Ignition system
- Manifold absolute pressure (MAP) sensor
- Injectors
- Air intake system/vacuum system - leaks
- Intake manifold air control solenoid(s)
- Heated oxygen sensor (HO2S)
- Engine control module (ECM)
KNOCK DURING ACCELERATOR
Component check sequence
- Engine management system - connections/wiring
- Knock sensor(s) (KS)
- Manifold absolute pressure (MAP) sensor
- Engine control module (ECM)
INCORRECT IDLE SPEED
Component check sequence
- Air intake system/vacuum system - leaks
- Evaporative emission (EVAP) canister purge valve
- Intake manifold air control solenoid(s)
- Electrical connections - engine/battery
- Engine management system - connections/wiring
- Throttle control unit
- Injectors
HESITATION WHEN ACCELERATING
Component check sequence
- Air intake system/vacuum system - leaks
- Intake manifold air control solenoid(s)
- Electrical connections - engine/battery
- Engine management system - connections/wiring
- Engine coolant temperature (ECT) sensor
- Fuel filter/fuel pump (FP)
- Fuel pressure/delivery rate
- Injectors
- Heated oxygen sensor (HO2S)
- Engine control module (ECM)
HESITATION ON OVERRUN
Component check sequence
- Electrical connections - engine/battery
- Engine management system - connections/wiring
- Engine coolant temperature (ECT) sensor
- Fuses/fuel pump (FP) relay/engine control (EC) relay
- Throttle control unit
- Injectors
- Intake manifold air control solenoid(s)
- Air intake filter
- Manifold absolute pressure (MAP) sensor
- Intake air temperature (IAT) sensor
- Engine control module (ECM)
HESITATION ON OVERRUN
Component check sequence
- Air intake system/vacuum system - leaks
- Intake manifold air control solenoid(s)
- Electrical connections - engine/battery
- Engine management system - connections/wiring
- Air intake filter
- Manifold absolute pressure (MAP) sensor
- Intake air temperature (IAT) sensor
- Engine coolant temperature (ECT) sensor
- Fuel filter/fuel pump (FP)
- Fuel pressure/delivery rate
- Injectors
- Engine control module (ECM)
EXCESSIVE FUEL CONSUMPTION
Component check sequence
- Air intake filter
- Engine coolant temperature (ECT) sensor
- Throttle control unit
- Engine management system - connections/wiring
- Manifold absolute pressure (MAP) sensor
- Intake air temperature (IAT) sensor
- Injectors
- Engine control module (ECM)
ERRATIC IDLING
Component check sequence
- Air intake system/vacuum system - leaks
- Evaporative emission (EVAP) canister purge valve
- Intake air temperature (IAT) sensor
- Intake manifold air control solenoid(s)
- Electrical connections - engine/battery
- Engine management system - connections/wiring
- Throttle control unit
- Engine coolant temperature (ECT) sensor
- Fuel pressure/delivery rate
- Injectors
- Engine control module (ECM)
- Manifold absolute pressure (MAP) sensor
ENGINE WILL NOT START
Component check sequence
- Immobilizer
- Inertia fuel shut-off (IFS) switch
- Electrical connections - engine/battery
- Engine management system - connections/wiring
- Fuses/fuel pump (FP) relay/engine control (EC) relay
- Fuel filter/fuel pump (FP)
- Ignition system
- Air intake system/vacuum system - leaks
- Manifold absolute pressure (MAP) sensor
- Injectors
- Fuel pressure/delivery rate
- Engine mechanical condition
- Exhaust system/catalytic converter
- Engine control module (ECM)
ENGINE STARTS THEN STOP
Component check sequence
- Electrical connections - engine/battery
- Air intake filter
- Air intake system/vacuum system - leaks
- Engine management system - connections/wiring
- Throttle control unit
- Fuel pressure/delivery rate
- Injectors
- Engine control module (ECM)
- Manifold absolute pressure (MAP) sensor
ENGINE DIFFICULT TO START -ENGINE WARM
Component check sequence
- Electrical connections - engine/battery
- Fuel filter/fuel pump (FP)
- Air intake system/vacuum system - leaks
- Evaporative emission (EVAP) canister purge valve
- Intake air temperature (IAT) sensor
- Engine management system - connections/wiring
- Engine coolant temperature (ECT) sensor
- Fuel pressure/delivery rate
- Injectors
- Engine control module (ECM)
ENGINE DIFFICULT TO START -ENGINE COLD
Component check sequence
- Electrical connections - engine/battery
- Fuses/fuel pump (FP) relay/engine control (EC) relay
- Fuel filter/fuel pump (FP)
- Crankshaft position (CKP) sensor
- Camshaft position (CMP) sensor
- Air intake system/vacuum system - leaks
- Intake air temperature (IAT) sensor
- Engine coolant temperature (ECT) sensor
- Manifold absolute pressure (MAP) sensor
- Fuel pressure/delivery rate
- Injectors
- Throttle control unit
- Engine management system - connections/wiring
- Engine control module (ECM)
CO LEVEL - TOO HIGH
Component check sequence
- Air intake filter
- Heated oxygen sensor (HO2S)
- Throttle control unit
- Engine coolant temperature (ECT) sensor
- Electrical connections - engine/battery
- Engine management system - connections/wiring
- Injectors
- Manifold absolute pressure (MAP) sensor
- Intake air temperature (IAT) sensor
- Evaporative emission (EVAP) canister purge valve
- Engine control module (ECM)
CO LEVEL - TOO LOW
Component check sequence
- Air intake system/vacuum system - leaks
- Heated oxygen sensor (HO2S)
- Air intake filter
- Throttle control unit
- Engine coolant temperature (ECT) sensor
- Fuel filter/fuel pump (FP)
- Fuel pressure/delivery rate
- Injectors
- Manifold absolute pressure (MAP) sensor
- Intake air temperature (IAT) sensor
- Engine management system - connections/wiring
- Engine control module (ECM)