Fuel Pressure Test

Release fuel system pressure. See FUEL SYSTEM PRESSURE RELEASE . On SOHC, remove air cleaner from throttle body. Disconnect fuel hose from throttle body. On DOHC, remove ISC solenoid valve and EGR modulator bracket (if equipped). See Figure & 2.
On all models, install fuel pressure gauge and 3-way connector between fuel feed hose and fuel return hose. See Fig 1 & 4. On SOHC, install air cleaner. On all models, verify battery voltage is at least 11 volts.

Fig 1: Testing Fuel Pressure (DOHC)
Courtesy of SUZUKI OF AMERICA CORP.

Fig 2: Testing Fuel Pressure (SOHC)
Courtesy of SUZUKI OF AMERICA CORP.
Remove fuel pump relay from fuse/relay box with harness connector installed. Fuse relay box is located in engine compartment, behind battery. Using jumper wire, connect Pink wire terminal to White/Blue wire terminal.
Turn ignition on. Fuel pressure should be within specification. See FUEL PUMP PERFORMANCE table. Turn ignition off. Recheck pressure after one minute. Fuel pressure should be within specification.
Remove jumper wire. Install ISC solenoid valve on DOHC models. On all models, start engine and warm it to normal operating temperature. Note fuel pressure with engine idling. Fuel pressure should be within specification.
If pressure is not within specification, check for defective fuel pump, pressure regulator or restriction in fuel system. Repair as required. Release fuel pressure, and remove fuel pressure gauge. Reconnect fuel hoses, and check for leaks.

FUEL PUMP PERFORMANCE

Application

At Idle: psi (kg/cm² )

Engine Off: psi (kg/cm² )

DOHC

⁽¹⁾ 25.6-30.0 (1.8-2.1)

35.5-38.4 (2.5-2.7)

SOHC

⁽²⁾ 12.8-20.0 (0.9-1.4)

22.7-30.0 (1.6-2.1)

⁽¹⁾	Pressure should remain at 25.6 psi (1.8 kg/cm² ) for one minute after fuel pump is turned off.

⁽²⁾	Pressure should remain at 12.8 psi (0.9 kg/cm² ) for one minute after fuel pump is turned off.