Fuel Pressure (Fuel System): Turbo

Ensure battery is fully charged. Release fuel pressure. See FUEL PRESSURE RELEASE under FUEL SYSTEM. Disconnect negative battery cable. Fuel pressure gauge is installed on fuel filter for checking fuel pressure. See Fig 1.
Place container under fuel filter. Cover union bolt with shop towel. Remove union bolt and gaskets. Using NEW gaskets, install Fuel Pressure Gauge (SST 09268-45014) with fuel inlet hose on fuel filter. See Fig 1. Tighten union bolt to 21 ft. lbs. (29 N.m). Install negative battery cable.
Connect scan tool to data link connector No. 3. See Figure. Turn ignition on. DO NOT start engine. Turn scan tool on. Select ACTIVE TEST MODE on scan tool. Using scan tool manufacturer's instructions, activate fuel pump and note fuel pressure. Fuel pressure should be 33-40 psi (2.3-2.8 kg/cm² ).
NOTE: Fuel pump may also be activated by connecting battery voltage to specified terminals on fuel pump. See Figure.
If fuel pressure is within specification, go to next step. If fuel pressure exceeds specification, replace fuel pressure regulator mounted on the fuel rail. See REMOVE/INSTALL/OVERHAUL article. If fuel pressure is less than specified, check for leaking fuel hoses or connections, restricted fuel filter, defective fuel pump or defective fuel pressure regulator.
Remove scan tool from data link connector No. 3. Start engine. Disconnect and plug vacuum hose at fuel pressure regulator mounted on fuel rail. Note fuel pressure with engine idling. Fuel pressure should be 33-40 psi (2.3-2.8 kg/cm² ).
Reconnect vacuum hose on fuel pressure regulator and note fuel pressure with engine idling. Fuel pressure should 24-31 psi (1.7-2.2 kg/cm² ). If fuel pressure is within specification, go to next step. If fuel pressure is not within specification, check for defective vacuum hose or fuel pressure regulator.
Shut engine off and note fuel pressure. Fuel pressure should remain at least 21 psi (1.5 kg/cm² ) for a minimum of 5 minutes. If fuel pressure holds as specified, go to next step. If fuel pressure does not hold as specified, check for defective fuel pump, fuel injector or fuel pressure regulator.
Release fuel pressure. Disconnect negative battery cable. Remove fuel pressure gauge. Using NEW gaskets, install fuel inlet hose on fuel filter. Tighten union bolt to 21 ft. lbs. (29 N.m). Install negative battery cable. Check for fuel leaks by using scan tool to energize fuel pump.

NOTE: For more information on checking fuel injectors and other fuel system components, see SYSTEM/COMPONENT TESTS article.

Fig 1: Installing Fuel Pressure Gauge (Turbo)