Isuzu N-Series. Manual - part 395

6C-58 FUEL SYSTEM

Governor Adjustment

N6A1657E

FUEL SYSTEM 6C-59

Injection Volume Adjustment (4HG1-T Engine)

Test Conditions

4HG1-T Engine

Identification Plate and Number

Use the data following the injection pump identification
number to adjust the injection volume.

Item

Condition

Injection nozzle and holder assembly

Bosch AS Part No.: 105118-7542

Injection nozzle

Bosch AS Part No.: 105019-1470

Nozzle holder

Bosch AS Part No.: 105048-3832

Injection nozzle opening pressure

kPa (kg/cm

2

 / psi)

18,044 (184 / 2,616)

Injection line dimensions

Inside diameter

mm (in)

2.2 (0.079)

Outside diameter

mm (in)

6.0 (0.236)

Length

mm (in)

600 (23.6)

Fuel delivery pressure

kPa (kg/cm

2

 / psi)

254.9 (2.6 / 36.97)

Test fuel

SAE Standard Test Diesel Fuel (SAE J967d)

ISO Standard Test Diesel Fuel (ISO 4113)

Test fuel temperature

°C (°F)

40 — 45 (104 — 113)

Identification numbers

101401-7452

Legend

A. Isuzu part No. (Pump assembly No.)
B. Bosch pump assembly No.

N6A0946E

6C-60 FUEL SYSTEM

Injection Volume and Governor Performance Diagram

Injection Volume

Timing Advance Specification

Identification Numbers

: 101401-7452

[4HG1-T Engine]

Pre-stroke

: No. 1 plunger 3.8

±0.05 mm (0.1496±0.0020 in)

Injection order

: 1 — 3 — 4 — 2 (interval 90

°±30′) Plungers are numbered from the Governor side

Tappet clearance

: Shim adjustment type

: Manually rotate the camshaft 2 — 3 times and confirm that it 
rotates smoothly.

: Bolt adjustment type

: More than 0.3 mm (0.0118 in) for all cylinders.

Adjusting 

point

Rack Posi-

tion 

(mm (in))

Pump 

Speed 

(rpm)

Injection q’ty (cm

3

/

1000strokes)

Max var 

bet. cyl. 

(%)

Fixed

Remarks

11.5 

(0.4528)

1000

73.5

±1.6

±4

Rack

Basic

H

Approx. 8.9 

(0.3504)

315

(Measure)

±1.3

±10

Rack

A

R1 (11.5 

(0.4528))

1000

73.5

±1

—

Lever

Basic Boost press. kPa (mmHg/
psi) 
Above 62.0 (465/8.99)

B

R1 +1.0 

(0.0394)

1500

(78.5)

±2

—

Lever

Lever Boost press. kPa (mmHg/
psi)
Above 62.0 (465/8.99)

C

R2 -0.8 

(0.0315)

500

(66.5)

±2

—

Lever

Boost press.
0

I

—

150

(Measure)

±16

—

Lever

Boost press.
0
Confirm that the timing of is
advanced 1

°±30′ from A.

Pump speed (rpm)

Below (N1 + 50)

N1

N3

Advance angle (

°)

Start

Below 0.5

Finish 4.0

±0.5

FUEL SYSTEM 6C-61

Governor Adjustment (4HG1-T)

N6A0955E