Fuel Pressure (Fuel System): Non-Turbo

Ensure battery is fully charged. Release fuel pressure. See FUEL PRESSURE RELEASE under FUEL SYSTEM. Disconnect negative battery cable. Note location of fuel inlet hose on fuel pipe support. See Fig 1.
Cover union bolt with shop towel. Slowly loosen union bolt to release fuel pressure. Remove union bolt with gaskets, and disconnect fuel inlet hose from fuel pipe support.
Using adapter union bolt and union from Fuel Pressure Gauge Set (SST 09268-45014) with gaskets, install fuel pressure gauge and fuel inlet hose. See Fig 1. Tighten adapter 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 44-50 psi (3.1-3.5 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 fuel pump in the fuel tank. 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 and note fuel pressure with engine idling. Fuel pressure should be 44-50 psi (3.1-3.5 kg/cm² ). If fuel pressure is within specification, go to next step. If fuel pressure is not within specification, check for by defective 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 adapter union bolt, union and fuel pressure gauge. Reinstall fuel inlet hose on fuel pipe support using NEW gasket. 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: Locating Fuel Inlet Hose & Installing Fuel Pressure Gauge (Non-Turbo)