CAUTION: Constant fuel pressure is maintained in fuel lines and component parts at all times. Relieve pressure before attempting to open system for testing. Do not allow fuel to flow onto engine or electrical parts or allow an open flame in area while testing fuel system components.

Disconnect negative battery cable. Unplug cold start injector electrical connector. Place container under fuel rail at union bolt of cold start injector hose.
Remove union bolt and drain fuel rail. Remove cold start injector hose from union bolt and install fuel pressure gauge with hose to union bolt. Install gauge and bolt to fuel rail with a gasket on each side of gauge fitting.
Connect battery cable and start engine. Disconnect vacuum line from fuel pressure regulator and pinch line closed. Gauge reading should be 38-44 psi (2.7-3.1 kg/cm² ) on Camry and Celica with 3S-FE engine or 33-38 psi (2.3-2.7 kg/cm² ) on all other models. If pressure is too high, replace fuel pressure regulator; if too low, check fuel system for leaks.
With engine idling, connect vacuum line to pressure regulator. Pressure reading should decrease to 35 psi (2.4 kg/cm² ) on Camry and Celica with 3S-FE engine or 28 psi (2.0 kg/cm² ) on all other models. If not, replace fuel pressure regulator. Stop engine. If pressure drops quickly, check fuel pump, pressure regulator, and injectors.

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.

Safety Warning

Fuel Pressure

Use the Manual With the Right Hardware

When to See a Mechanic

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