Isuzu KB P190. Manual - part 610

6E–270

ENGINE DRIVEABILITY AND EMISSIONS

FUEL PRESSURE RELIEF

Caution: To reduce the risk of fire and personal
injury, it is necessary to relieve the fuel system
pressure before servicing the fuel system
components.
Caution: After relieving the fuel system pressure, a
small amount of fuel may be released when
servicing fuel lines or connections. Reduce the
chance of personal injury by covering the fuel line
fitting with a short towel before disconnecting the
fittings. The towel will absorb any fuel that may leak
out. When the disconnect is completed, place the
towel in an approved container.

1. Remove the fuel filler cap.

2. Remove the fuel pump relay from the underhood

relay box.

3. Start the engine and allow it to stall.

4. Crank the engine for about 30 seconds.

5. Disconnect the negative battery cable.

FUEL RAIL ASSEMBLY

Removal Procedure
NOTE: 

• Use care when removing the fuel rail assembly in

order to prevent damage to the injector al connector
terminal and the injector spray tips.

• Fitting should be capped and holes plugged during

servicing to prevent dirt and other contaminants from
entering open lines and passage.

Important: An eight-digit identification number is
stamped on side of the fuel injector. Refer to this
number when you service the fuel rail or when a
replacement part is required.

1. Disconnect 4 injector connectors.

2. Lift side-clip up on the fuel rail.

3. Disconnect fuel pressure regulator hose.

4. Disconnect wiring harness from the bands on the

fuel rail.

5. Remove the intake pipe.

6. Loosen flare nut.

A. Lift up the injectors carefully to separate them

from intake manifold.

B. Lift up the fuel rail with injectors as assembly.

Do not separate the fuel injectors from fuel rail.

C. If an injector become separated from fuel rail,

injector backup O-ring and injector retainer clip
must be replaced.

D. Drain residual fuel from fuel rail into an

approved container.

7. If removal of fuel pressure regulator is necessary,

Refer to Fuel Pressure Regulator Removal
Procedure.

ENGINE DRIVEABILITY AND EMISSIONS

6E–271

8. If removal of fuel injector is necessary, Refer to Fuel

Injectors Removal Procedure.

Installation Procedure

1. Install the fuel injectors if necessary. Refer to Fuel

Injector Installation Procedure.

2. Install the fuel pressure regulator if necessary. Refer

to Fuel Pressure Regulator Installation Procedure.

3. Place the fuel injector rail assembly on the manifold

and insert the injectors into each port by pushing
fuel rail.

4. Install two fuel rail retaining bolts. Tighten fuel rail

retaining bolt to 19 N·m (1.9kgf·m)

5. Place wiring harness in its place and secure it with

two nuts.

6. Connect all connector to each fuel injector.

7. Connect the fuel supply line securely. Do not over

tighten.

8. Connect the fuel return line securely. Do not over

tighten.

9. Connect the negative battery cable.

10. Crank the engine until it starts. Cranking the engine

may take longer than usual due to trapped air in the
fuel system. Check for leak. If fuel leak is observed,
stop engine immediately. Before correcting fuel
leak, be sure to depressurize system again.

6E–272

ENGINE DRIVEABILITY AND EMISSIONS

FUEL INJECTOR

Removal Procedure
NOTE: If the fuel injectors are leaking, the engine oil
may be contaminated with fuel. Check the oil for signs
of contamination and change the oil and filter if
necessary.

NOTE: Use care in removing the fuel injector in order to
prevent damage to the fuel injector al connector pins or
fuel injector nozzles. The fuel injector is an al
component and should not be immersed in any type of
cleaner as this may damage the fuel injector.

Important:  Fuel injectors are serviced as complete
assembly only.

1. Disconnect the negative battery cable.

2. Disconnect al connector from fuel injector.

3. Remove the fuel rail. Refer to Fuel Rail Removal

Procedure.

4. Remove the fuel injector retainer clip.

5. Remove the fuel injector assembly from fuel rail.

6. Remove O-ring from the fuel injector.

7. Remove O-ring backup from fuel injector.

Inspection

1. Inspect O-ring for crack, damage or leaks.

2. Replace worn or damaged O-ring.

3. Lubricate the new O-rings with engine oil before

installation.

Installation Procedure

1. Lubricate the new O-ring with engine oil.

2. Install the O-ring backup on the fuel injector.

3. Install new O-ring on the fuel injector.

4. Install all four injector on the fuel rail.

5. Use new injector retainer clip to retain the injetor to

the fuel rail.

6. Coat the end of the fuel injector with engine oil.

ENGINE DRIVEABILITY AND EMISSIONS

6E–273

7. Install fuel rail assembly. Tighten the nuts to 19 N·m

(1.9 kgf·m). Refer to Fuel Rail Installation
Procedure.
Tighten the flare nut to 27 - 33 N·m (2.8 - 3.4 kgf·m).

8. Connect the negative battery cable.

FUEL PRESSURE REGULATOR

Removal Procedure
Caution: To reduce the risk of fire and personal
injury, it is necessary to relieve the fuel system
pressure before servicing the fuel system
components.
Caution: After relieving the fuel system pressure, a
small amount of fuel may be released when
servicing fuel lines or connections. Reduce the
chance of personal injury by covering the fuel line
fitting with a shop towel before disconnecting the
fittings. The towel will absorb any fuel that may leak
out. When the disconnect is completed, place the
towel in an approved container.

NOTE: Compressed air must never be used to test or
clean a fuel pressure regulator, as damage to the fuel
pressure regulator may occur.

NOTE: To prevent damage to the fuel pressure
regulator, do not immerse the pressure regulator in
solvent.

Removal Procedure

1. Depressurize the fuel system. Refer to Fuel

Pressure Relief Procedure.

2. Disconnect the negative battery cable.

3. Remove the fuel pump relay.

4. Disconnect the vacuum line form fuel pressure

regulator.