To fix or repair the engine's lower intake manifold, reduce fuel system pressure and then take off the upper intake manifold. Get rid of the connectors linking the
Fuel Injectors to the wires and remove the supply hose from the
Fuel Rail. Then, unscrew and remove the mounting screw from the fuel rail support bracket to the throttle body support bracket and remove the bolts securing the fuel rail. Lift out the pair of injectors and fuel rail together first and afterward remove the nuts securing the manifold and take out the lower manifold. Let's check the manifold for any holes, cracks, gasket surface wear-out or warpage; again, change the manifold if we locate any of these problems. While installing, look at and clean the head and manifold gasket areas, putting back the gasket if it's undamaged. Set the manifold on top of the cylinder head and then add a bolt 2 - 3 turns into the innermost attaching hole to hold the lower manifold in place as you install the rest of the bolts. Place the fuel rail and injectors before fastening the manifold attaching bolts. Make sure you tighten each bolt according to the order given, then take out the alignment bolt. Connect the electrical connections on the fuel injectors so the injectors stay in the right position and do not bump into the upper intake manifold. Connect the screw for the fuel rail support bracket to the throttle body support bracket, put the fuel supply hose onto the fuel rail and finish with the upper intake manifold.