Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
System Inspection
- 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.
- Visually/physically inspect the air leakage in intake/exhaust system for following items
- 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 the fuel line for following items
- Check fuel pressure NOTE:
- 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 personal injury or fire damage to vehicle components.
- IG "OFF" and disconnect Fuel Pump Relay in Junction Box.
- Start-up and wait until it stops itself.
- IG "OFF" and connect Fuel Pump Relay.
- Install the fuel pressure gauge to the delivery pipe with the fuel pressure gauge adaptor.
- Activate the fuel pump, and with fuel pressure applied, check that there is no fuel leakage from the pressure gauge or connection part.
- Measure the fuel pressure at idle.
Specification: 374.6 ~ 384.4 kPa (3.82 ~ 3.92 kg/cm2 , 54.3 ~ 55.8 psi)
- Is the measured fuel pressure within specifications?
YES
Go to "COMPONENT INSPECTION " procedure.
NO
Repair or replace according to the below table. And then, go to "VERIFICATION OF VEHICLE REPAIR " procedure.
Condition Possible Cause Fuel Pressure is too low Fuel filter, fuel pressure regulator, in-tank fuel hose or the fuel pump Fuel Pressure is too high Fuel pressure regulator, hose or pipe
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.