SFI SYSTEM PROBLEM SYMPTOMS TABLE

Tech Tips


  • Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.

  • Inspect the fuses and relays related to this system before inspecting the suspected areas below.

SFI System
Symptom Suspected Area Link
Engine does not crank (does not start) Hybrid control system

Click here

VC output circuit

Click here

No initial combustion (does not start) ECM power source circuit

Click here

VC output circuit

Click here

Crank position sensor

Click here

Valve timing (check for loose or jumped teeth on timing chain)

Click here

Ignition system

Click here

Fuel pump control circuit

Click here

Fuel injector circuit

Click here

Engine cranks normally but difficult to start Fuel pump control circuit

Click here

Engine coolant temperature sensor

Click here

Ignition system

Click here

Compression

Click here

Fuel injector assembly

Click here

Fuel injector circuit Click here
Intake system

Click here

Throttle body assembly

Click here

PCV valve and hose

Click here

EGR valve assembly

Click here

ECM power source circuit

Click here

Incomplete intermittent combustion occurs (does not start) Fuel pump control circuit

Click here

Fuel pump

Click here

Fuel line -
Ignition system

Click here

Fuel injector circuit

Click here

EGR valve assembly

Click here

ECM power source circuit

Click here

Crank position sensor

Click here

Valve timing (check for loose or jumped teeth on timing chain)

Click here

High engine speed Throttle body assembly

Click here

Intake system

Click here

ECM power source circuit

Click here

Engine coolant temperature sensor

Click here

PCV system

Click here

Low engine speed (poor idle) Throttle body assembly

Click here

Fuel pump control circuit

Click here

Fuel pump

Click here

Intake system

Click here

PCV system

Click here

Rough idle Compression

Click here

Ignition system

Click here

Fuel injector circuit

Click here

ECM power source circuit

Click here

Fuel pump control circuit

Click here

Fuel pump

Click here

Fuel line -
Throttle body assembly

Click here

Intake system

Click here

PCV system

Click here

Air fuel ratio sensor

Click here

Heated oxygen sensor

Click here

Mass air flow meter sub-assembly

Click here

Manifold absolute pressure sensor Click here
Knock control sensor

Click here

EGR valve assembly

Click here

Hunting (poor idle) PCV system

Click here

Air fuel ratio sensor

Click here

Mass air flow meter sub-assembly

Click here

Hesitation and/or poor acceleration Fuel line -
Fuel pump Click here
Valve timing (check for loose or jumped teeth on timing chain) Click here
Mass air flow meter sub-assembly Click here
Throttle body assembly Click here
Knock control sensor Click here
Brake override system Click here
Surging (poor driveability) Fuel line -
Fuel pump control circuit Click here
Fuel pump Click here
Ignition system Click here
Fuel injector assembly

Click here

Engine stalls soon after starting Mass air flow meter sub-assembly

Click here

Intake system

Click here

Manifold absolute pressure sensor

Click here

Fuel line -
Valve timing (check for loose or jumped teeth on timing chain)

Click here

EGR valve assembly

Click here