Verify that there is fuel in the fuel tank and that the fuel pump actually runs. When turning the ignition switch to ON, a brief whirring noise should emanate for about two seconds as the pump activates and pressurizes the system. For models without a Schrader valve, you'll require a fuel pressure gauge, a tee-fitting, short sections of approved fuel hose, and appropriate hose clamps. After relieving the system fuel pressure, disconnect the cable from the negative battery terminal. On Sephia and Spectra models, locate the fuel filter on the firewall and trace the hose to the fuel rail, then disconnect the fuel supply hose. On Sportage models, locate the supply line at the left end of the front fuel rail and trace it back to the threaded fitting below the brake master cylinder. Integrate your fuel pressure gauge between the disconnected fuel supply hose and the fuel rail. After reconnecting the negative battery terminal and turning on the ignition, the gauge should display pressure. For checking the operation of the fuel pressure regulator, monitor the gauge when the vacuum hose from the regulator is disconnected. The pressure should increase by 3 to 10 psi. On models with a Schrader valve, after connecting the fuel pressure gauge to the fuel rail test port, activate the ignition switch and note the pressure on the gauge. If it's low, inspect the fuel supply hose, replace the fuel filter, and subsequently the fuel pump or regulator as needed. If high, replace the regulator. Once testing is completed, ensure the negative battery terminal is reconnected, and start the engine to check for fuel leaks.
