Release fuel pressure. See FUEL SYSTEM PRESSURE RELEASE . Disconnect PCV hose and Intake Air Temperature (IAT) sensor connector. Remove air cleaner assembly. Remove fuel inlet hose from throttle body. Install Fuel Pressure Gauge (J-34730-1) and Adapter (J-34730-75). See Fig 1 .
Reconnect negative battery cable. Start engine and idle at normal operating temperature. Check fuel pressure. See FUEL PUMP PERFORMANCE table. If fuel pressure is not as specified, go to appropriate ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK chart. If fuel pressure is as specified, release fuel pressure. Remove fuel pressure gauge and reinstall components removed. Start engine and check for leaks.

Fig 1: Installing Fuel Pressure Gauge (Metro)

Courtesy of GENERAL MOTORS CORP.

FUEL PUMP PERFORMANCE

KOEO ⁽¹⁾ psi (kg/cm² )

Engine @ Idle psi (kg/cm² )

⁽²⁾ Hold Pressure psi (kg/cm² )

23-31 (1.6-2.2)

13-20 (.9-1.4)

13 (.9)

⁽¹⁾	KOEO is ignition on and engine off.

⁽²⁾	Measured within one minute of engine off and with ignition on.

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