Fuel Delivery and Air Induction: Service Precautions

3MZ-FE FUEL SYSTEM:

PRECAUTION

1. PRECAUTION
(a) Before working on the fuel system, disconnect the cable from the negative (-) battery terminal.
(b) Do not smoke or be near an open flame when working on the fuel system.
(c) Keep gasoline away from rubber or leather parts.
2. DISCHARGE FUEL SYSTEM PRESSURE

NOTICE:
- Do not disconnect any part of the fuel system until you have discharged the fuel system pressure.
- Even after discharging the fuel pressure, place a shop rag over fittings as you separate them to reduce risk of fuel spray on yourself or in the engine compartment.





(a) Remove the C/OPN relay from the engine room J/B.

(b) Start the engine. After the engine has stopped, turn the ignition switch OFF.

HINT: In some cases, DTC P0171 (system to lean) is output.

(c) Check that the engine does not start.
(d) Remove the fuel tank cap, and let the air out of the fuel tank.
(e) Disconnect the cable from the negative (-) battery terminal.

NOTE: When disconnecting the cable, some systems need to be initialized after the cable is reconnected (Repair Instruction - Initialization).

(f) Reinstall the C/OPN relay.
3. FUEL SYSTEM
(a) When disconnecting the high fuel pressure line, a large amount of gasoline will spill out. Follow these procedures.
(1) Try to prevent gasoline from spilling out.
(2) Disconnect the fuel pump tube.
(3) Drain the fuel remaining inside the fuel pump tube. (Removal)





(4) To protect the disconnected fuel pump tube from damage and contamination, cover it with a vinyl bag.

(5) Put a container under the connection.





(b) Observe these precautions when removing and installing the injector.
(1) Never reuse the O-rings.
(2) When placing a new O-ring on the injector, take care not to damage it in any way.
(3) Coat new O-rings with grease or gasoline before installing. Never use engine, gear or brake oil.





(c) Install the injector to the delivery pipe and intake manifold, as shown in the illustration. Before installing the injector, be sure to apply grease or gasoline on the place where the delivery pipe touches the O-ring of the injector.

(d) Observe the following precautions when disconnecting the fuel tube connectors (Quick Type A):





(1) Remove the No. 1 fuel pipe clamp.

(2) Check that there is no dirt or other foreign objects on the pipe and around the connector before disconnecting them. Clean them if necessary.





(3) Disconnect the connector from the pipe by hand.

(4) If the connector and the pipe are stuck, push in and pull on the connector to release it. Pull the connector out of the pipe carefully.
(5) Check that there is no dirt or other foreign objects on the sealing surface of the disconnected pipe. Clean the surfaces if necessary.





(6) Do not damage the disconnected pipe or connector. Prevent entry of foreign objects by covering the connectors with plastic bags.





(e) Observe the following precautions when connecting the fuel tube connectors (Quick Type A):
(1) Check if there is any damage or foreign objects on the connecting parts of the pipes.
(2) Line up the two parts of the pipes to be connected, and push them together until the connector makes a "click" sound. If the pipe is difficult to push into the connector, apply a small amount of clean engine oil to the tip of the pipe and reinsert it.
(3) After connecting the pipes, check that the pipe and connector are securely connected by pulling on them.
(4) Inspect for fuel leak.

(f) Observe the following precautions when disconnecting the fuel tube connector (Quick Type B):





(1) Before disconnecting the connector, clean off any dirt that may be present.
(2) Pinch the tabs of the fuel tube retainer to disengage the 2 claws. Push the retainer down as shown in the illustration.

HINT: Be sure to disconnect the connector by hand.





(3) If the connector and pipe are stuck, hold the fuel pipe by hand, and push and pull on the connector. Pull the two pipes apart to separate the connector.

(4) Check if there is any dirt or any other foreign objects on the sealing surfaces of the disconnected pipes. Clean the sealing surfaces if necessary.





(5) Do not damage the disconnected pipe or connector. Prevent entry of foreign objects by covering the connectors with plastic bags.

(g) Observe the following precautions when connecting the fuel tube connector (Quick Type B):





(1) Line up the two parts of the pipes to be connected, and fully push the fuel tube connector and pipe together until they are fully seated. Next, push the retainer into the connector until its claws lock. If the pipe is difficult to push in to the connector, apply a small amount of clean engine oil to the tip of the pipe and reinsert it.

(2) After connecting the pipes, check that the pipe and connector are securely connected by pulling on them.
(3) Inspect for fuel leak.
(h) Observe the following precautions when handling a nylon tube:

CAUTION:
- Do not twist the connector part of the nylon tube or the quick connector when connecting them.
- Do not bend or twist the nylon tube.
- Do not remove the EPDM protector on the outside of the nylon tube.
- Do not pinch or kink the nylon tubes to prevent fuel leaks.

4. INSPECT FOR FUEL LEAK
(a) Check that there are no fuel leaks after doing any maintenance or repairs (Removal).