To work on the throttle body, start by detaching the negative battery cable and relieving fuel pressure. Disconnect the flexible air duct and unplug the idle speed stepper motor and throttle position sensor wire connectors. Remove the MAP sensor vacuum tube from the throttle body and detach the throttle linkage, and if there's an automatic transmission, detach the line pressure cable. Then, remove the mounting bolts, throttle body, and gasket, making sure to discard the old gasket and clean the mating surfaces on the throttle body and intake manifold. For the idle speed stepper motor, disconnect the negative battery cable, unplug the wire connector, remove the retaining screws, and pull off the motor. Installation is the reverse of removal. To work on the throttle position sensor, detach the negative battery cable, unplug the TPS wire connector, and remove the retaining screws while bending back the TPS lock tabs if present. Then, detach the TPS from the throttle plate assembly and have it adjusted by a dealer service department. For the fuel injector rail assembly, relieve fuel tank pressure and system fuel pressure, disconnect the negative battery terminal, numerically label and unplug the injector harness connectors, detach the vacuum tube from the fuel pressure regulator, and remove the fuel supply hose, fuel return line from the intake manifold, and fuel return line from the fuel pressure regulator. Remove the fuel rail mounting bolts, and if there's an automatic transmission, consider removing the automatic transmission line pressure cable and bracket to remove the fuel rail assembly. Carefully remove the fuel rail by rocking and pulling up on it until all injectors are out of the intake manifold, and then installation is the reverse of removal, ensuring proper seating of the injectors and using a new O-ring, spacer, and retainer repair kit when reattaching the fuel lines. To work on the fuel injector, follow the steps to relieve fuel pressure and detach the negative battery cable, and remove the fuel injector rail assembly. Remove the retaining clip(s) from the injectors and replace the O-rings and seals, ensuring you use the correct ones from the kit and coat them with a little fuel before installing the injectors. For the fuel pressure regulator on 1995 and earlier models, relieve fuel tank pressure and system fuel pressure, disconnect the negative battery terminal, and remove the regulator retaining screws or clip. Pull the regulator off the fuel rail, replace the O-ring, and install it with a new one before reinstallation. On 1996 and later models, the regulator is integrated with the fuel pump module and cannot be serviced separately. For 1997 and later models, relieve fuel pressure, remove the fuel tank, disconnect the fuel line, pry the retainer clamp loose, carefully remove the filter/regulator, replace the gasket, and ensure the new filter/regulator has both O-rings in place and apply clean engine oil to them before installation. Reattach the retainer clamp and complete the rest of the installation in reverse.
