Check air leakage
Visually/physically inspect the air leakage in intake/exhaust system for following items
▶ Vacuum hoses for splits, kinks and improper connections.
▶ Throttle body gasket
▶ Gasket between intake manifold and cylinder head
▶ Seals between intake manifold and fuel injectors
▶ Exhaust system between HO2S and three way catalyst for air leakage
Has a problem found in this procedure?
YES
▶ Repair or replace it which has a problem, and go to "Verification of Vehicle Repair" procedure.
NO
▶ Go to "Check the fuel line" as follows
Check the fuel line
Check the fuel line for following items
▶ Connector connection state
▶ Damage/ connection state for vacuum hoses connected to fuel line
▶ Bent/ pressed/ twisted fuel line or fuel leakage
Has a problem found in this procedure?
YES
▶ Repair or replace it which has a problem, and go to " Verification of Vehicle Repair" procedure.
NO
▶ Go to "Check fuel pressure" as follows
Check fuel pressure
Be cautious that Fuel is explosive and an empty fuel tank can still contain explosive gases.When working on fuel system make sure to supply adequate ventilation to the work area. Do not smoke, and keep sparks and open flames away.
The fuel system remains under pressure when the engine is not running. Release fuel system pressure before disconnecting any fuel line to reduce the chance of presonal injury or fire damage to vehicle components.
Start the engine and disconnect the fuel pump relay.
Wait until fuel in fuel line is exhausted and the engine stalls.
Turn the ignition switch OFF position.
Install the fuel special service tool for measuring the fuel pressure between the delivery pipe and the fuel feed hose.
Connect the fuel pump relay.
With fuel pressure applied, check that there is no fuel leakage from the fuel pressure gauge or connection part.
Start the engine and measure the fuel pressure at idle
Specifications : 374 ~ 384 kPa(3.82 ~ 3.92 kg/cm², 54.3 ~ 55.8 psi)
Stop the engine and check for a change in the fuel pressure gauge reading.
Specifications : After engine stops, the gauge rdading should hold for about 5 minutes.
Is the measured fuel pressure within specifications ?
YES
▶ Go to "Component Inspection" procedure.
NO
▶ Repair or replace according to the table below.
Condition | Possible Cause | Suspected area |
Fuel pressure too low | Clogged fuel filter | Fuel filter |
Fuel leak on the fuel-pressure regulator that is assembled on fuel pump because of poor seating of the fuel-pressure regulator | Fuel pressure regulator | |
Fuel pressure too high | Sticking fuel pressure regulator | Fuel pressure regulator |
Fuel pressure drops slowly after engine is stopped | Injector leak | Injector |
Fuel pressure drops immediately after engine is stopped | The check valve within the fuel pump is open | Fuel pump |
