Tips for Replacing Toyota Fuel Injectors

The Toyota has several models and each model, depending on the year, has several different engines, including the 1MZ-FE engine - a V6 engine found in Toyotas from 1994 through 2000. The 1MZ-FE is found in the Camry, Avalon, Harrier (non-U.S. markets), Sienna, Solara and the Estima (Japanese domestic market only). When working with the fuel system on any of the Toyota vehicles, it is imperative to relieve the fuel pressure before beginning work.

Step 1: Locate the relay box near the driver's side fender well. Using the diagram on the underside of the cover, locate the fuel pump relay. Pull the relay out of the box. Start the Toyota and let it run until it stalls, to relieve the pressure in the fuel system.

Step 2: Park the vehicle and turn off its ignition. Open and secure the vehicle's hood. Slide the drain pan under the radiator. Remove the radiator cap, then loosen the petcock and allow the radiator to drain into the drain pan. If the coolant is less than 5 years old and the drain pan is clean, you can reuse the coolant.

Step 3: Remove the negative battery cable, using the appropriate wrench, and set it aside, ensuring that it does not touch metal. If your year and model vehicle has an air bag, wait 90 seconds before proceeding to allow the air bag system time to lose complete power.

Step 4: Remove the accelerator and throttle cables from the slot in the throttle body, using your fingers. Unbolt and remove the air cleaner assembly, using the appropriate sockets. Remove the V-bank cover, using the appropriate socket.

Step 5: Remove the emission valve control set and the No. 2 EGR pipe, using the appropriate sockets and wrenches. Remove the hydraulic motor pressure pipe from the water inlet and the air inlet chamber, using the appropriate socket. Remove the air intake chamber assembly.

Step 6: Unplug the fuel injector wiring harness from each fuel injector. Remove the air assist pipe from the No. 1 fuel pipe, using the appropriate wrench. Remove the air assist hoses from the intake manifold, using the appropriate socket. Loosen the clamp on the fuel return hose for the No. 1 fuel pipe, using the appropriate socket, then pull the hose off.

Step 7: Loosen the clamps on the fuel inlet hose for the fuel filter, then pull the hoses off the filter. Remove the two union bolts that hold the No. 2 fuel pipe to the delivery pipes. Loosen the clamp on the fuel return hose from the fuel pressure regulator, then pull the hose off.

Step 8: Remove the union bolt for the right delivery pipe, the two gaskets, two bolts and the entire left delivery pipe, while pulling the three injectors and the No. 2 fuel pipe out at the same time.

Step 9: Remove the union bolt for the delivery pipe and the two gaskets from the No. 2 fuel pipe, using the appropriate socket. Remove the three bolts and the right delivery pipe at the same time as the three injectors and the No. 1 fuel pipe.

Step 10: Pull the four spacers off the intake manifold. Remove the six fuel injectors from the delivery pipes.

Step 11: Slide the new grommets on each new injector. Coat the O-rings with a light coat of fuel, then slide them on each new injector. Put new grommets and O-ring on injectors that are not going to be replaced. Insert each injector into the injector rail.

Step 12: Reinstall the four spacers on the intake manifold. Set the right delivery pipe and the No. 1 fuel pipe, which has three of the injectors, in place on the intake manifold. Insert the bolt that holds the right side delivery pipe into the intake manifold, but do not tighten it. Set the left delivery pipe and its three fuel injectors into position on the intake manifold.

Step 13: Attach the fuel return hose to the fuel pressure regulator. Screw in the two bolts that hold the left delivery pipe to the intake, but do not tighten them. Reinstall the No. 2 fuel pipe on the left side delivery pipe, using the union bolt and two new gaskets. Make sure the injectors rotate smoothly.

Step 14: Position the injector connectors outward, then tighten the four bolts that hold the delivery pipes on the intake manifold to 7 foot-pounds of torque. Tighten the bolt that hold the No. 1 fuel pipe onto the intake manifold to 14 foot-pounds of torque. Tighten the two union bolts that hold the No. 2 fuel pipe to the delivery pipe to 24 foot-pounds of torque.

Step 15: Reinstall the fuel inlet and return hoses. Tighten the union bolt to 22 foot-pounds of torque. Install the fuel return hose on the No. 1 fuel pipe, then pass the fuel return hose under the heater hoses. Reinstall the air assist hoses on the intake manifold, the air assist pipe to the intake manifold, and the air assist pipe to the bracket on the No. 1 fuel pipe.

Step 16: Plug in the fuel injector wiring connectors. Reinstall the air intake chamber assembly. Reattach the hydraulic motor pressure pipe onto the intake chamber and tighten the bolts to 69 inch-pounds of torque.

Step 17: Reinstall the No. 2 EGR pipe, using new gaskets, then tighten the bolts to 9 foot-pounds of torque. Reinstall the emission control valve set, V-bank cover, air cleaner hose and the throttle and accelerator cables. Reattach the negative battery cable and plug in the fuel pump relay.