System Inspection

Check air leakage
1. 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 leak between Heated Oxygen Sensor (HO2S) and three-way catalyst
2. Has a problem been found?
  YES
  - Repair or replace. Then, go to "VERIFICATION OF VEHICLE REPAIR " procedure.
  NO
  - Go to " 2 Fuel Line Inspection" procedure.
Fuel Line Inspection
1. Check the fuel line for following items
  - Connector connection state
  - Bent, pressed or twisted fuel line or fuel leakage
2. Has a problem been found?
  YES
  - Repair or replace. Then, go to "VERIFICATION OF VEHICLE REPAIR " procedure.
  NO
  - Go to " 3 Fuel Pressure Inspection" procedure.

Fuel Pressure Inspection

NOTE:

Be cautious as fuel is explosive and an empty fuel tank can still contain explosive gases. When working on fuel systems 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 personal injury or fire damage to vehicle components.

IG "OFF" and disconnect Fuel Pump Relay in Junction Box.
Start engine and wait until it stalls.
IG "OFF" and reconnect Fuel Pump Relay.
Install the fuel pressure gauge to the delivery pipe with the correct adaptor(s).
Activate the fuel pump and check that there is no fuel leakage from the pressure gauge or connections.
Measure the fuel pressure at idle.
Specification : 55.0 psi

Is the measured fuel pressure within specifications?

YES

Go to "COMPONENT INSPECTION " procedure.

NO

Repair or replace according to the table below. Then, go to "VERIFICATION OF VEHICLE REPAIR " procedure.

PROBLEM SYMPTOMS

Condition	Possible Cause
Fuel pressure is too low	Fuel filter, fuel pressure regulator, in-tank fuel hose or fuel pump
Fuel pressure is too high	Fuel pressure regulator, hose or pipe