Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual — part 595

FUEL SYSTEM 6C – 39

INSPECTION AND ADJUSTMENT (AFTER
DISASSEMBLY)

Adjustment of nozzle opening pressure, inspection for
leakage and spray condition should be explained.

Adjustment of nozzle opening pressure

Install injection nozzle and nozzle holder assembly to
nozzle tester.
Adjust the nozzle opening pressure by setting pressure
adjusting shim until desired pressure is obtained.
Check nozzle openinig pressure by pumping tester lever
once per second.
Nozzle opening pressure can be changed by:
1. Change of adjusting shim thickness at the rate of 4.8

kg/cm2 (68.3 psi/470.9 kpa) every thickness change
of adjusting shim by 0.04 mm (0.0016 in.).

2. Adding one 0.05 mm shim to increase 6 kg/cm

2

(85.3

psi/588.6 kpa).

Nozzle opening pressure of injection nozzles:

150 kg/cm

2

(2,133 psi/14.7 MPa)

Adjusting shims used for injection nozzle assembly.

Adjusting Shim Available

mm (in)

SHIM THICKNESS

IDENTIFICATION

MARK ON SHIM

0.50

(0.0197)

0.54 (0.0213)

↓

0.94 (0.0370)

0.98 (0.0386)

1.00 (0.0394)

0.05 (0.0020)

50

54

↓

94

98

00

NONE

6C – 40 FUEL SYSTEM

INJECTION NOZZLE

(For 4JA1TC, 4JH1TC Engine)

DISASSEMBLY

080L200009

Disassembly Steps

1.

Retaining nut

9.

Collar

2.

Nozzle & pin

10.

Spring seat

3.

Spacer & pin

11.

First spring

4.

Lift Piece

12.

Shim (First nozzle opening
pressure adjustment)

5.

Spring seat

13.

Nozzle holder body

6.

Push rod

14.

Eye bolt

7.

Shim (Second nozzle opening
pressure adjustment)

15.

Gasket

8.

Second spring

Important Operations

The two-spring nozzle holder has been developed to
reduce NOx (Nitrogen Oxides) and particulates from direct
injection diesel enigne exhaust.
Before disassembly remove carbon deposit from nozzle
and nozzle holder using a wire brush and wash the outside
nozzle holder assembly.
Caution:
Do not touch nozzle holes with the wire brush during
cleaning it.
Disassemble the nozzle holder assembly to numerical
order.

FUEL SYSTEM 6C – 41

REASSEMBLY

080L200010

Reassembly Steps

1.

Nozzle holder body

9.

Spring seat

2.

Shim (First opening pressure
adjustment)

10.

Lift Piece

3.

First spring

11.

Spacer & pin

4.

Spring seat

12.

Nozzle & pin

5.

Collar

13.

Retaining nut

6.

Second spring

14.

Gasket

7.

Push rod

15.

Eye bolt

8.

Shim (Second opening pressure
adjustment)

Important Operations

The nozzle holder is adjusted as the components are
reassembled in the sequence above.
As adjustment of the two-spring nozzle holder is made in
hundredths of a millimeter, clean the parts thoroughly in
light oil to completely remove any dirt or foreign matter.

6C – 42 FUEL SYSTEM

REASSEMBLY AND ADJUSTMENT PROCEDURE

1

First nozzle opening pressure adjustment

Adjust the first nozzle opening pressure using the shim.

2

Full needle valve lift confirmation

Confirm the full needle valve lift in accordance with the
closed method.

3

Pre-lift confirmation

Confirm pre-lift in accordance with the closed method.

CAUTION:
If not as specified, replace the nozzle assembly, lift
piece, pins and spacer using the nozzle service kit.

4

Second nozzle opening pressure

confirmation

Confirm the second nozzle opening pressure in accordance
with the closed method.

5

Second nozzle opening pressure

adjustment

Adjust the second nozzle opening pressure using the shim.

6

Final inspection

Confirm the condition of the fuel spray with the nozzle and
nozzle holder assembled.

First nozzle opening pressure adjustment

Nozzle needle valve full-lift

0.25 mm (0.0098 in)

Nozzle needle valve pre-lift

0.04 mm(0.0016 in) at 204 kg/cm

2

(2901 psi, 20,000 kpa)

Nozzle pressure 1st Stage

4JA1TC : 199−209 kg/cm

2

(2830−2972 psi, 19.5−20.5 Mpa)

4JH1TC : 204−214 kg/cm

2

(2901−3043 psi, 20.0−21.0 Mpa)

2nd Stage

4JA1TC : 347−362 kg/cm

2

(4934−5148 psi, 34.0−35.5 Mpa)

4JH1TC : 350−365 kg/cm

2

(4977−5190 psi, 34.3−35.8 Mpa)

at lift 0.09 mm (0.0035 in)
= (pre lift + 0.05 mm (0.0020 in))