Isuzu KB P190. Manual - part 638

Engine Mechanical – V6 

Page 6A1–73 

 

7 

Remove the fuel rail and injector assembly. Refer to 
6C1-3 Engine Management – V6 – Service 
Operations. 

 

The following precautions must be followed 
when removing the fuel rail and injector 
assembly: 
• 

Care must be taken when removing the 
fuel rail and injector assembly to 
prevent damage to the injector spray 
tips and injector harness connector 
terminals. 

• 

Support the fuel rail and injector 
assembly after removal. 

• 

Plug all fuel line and manifold openings 
after removal to prevent dirt and other 
contaminants from entering the fuel 
system. 

 

Figure 6A1 – 53 

Clean 

CAUTION

 

Due to the aluminium alloy construction of 
the intake manifold, wire brushes and steel 
scrapers must not be used during the 
cleaning process, as damage to sealing 
surfaces may occur. Use of a wooden or 
plastic scraper is preferred. 

1 

Clean mating surfaces ensuring any gasket material is removed. 

2 

Clean the manifold using a suitable solvent 

 

Safety glasses must be worn when using 
compressed air. 

3 

Dry the timing components with compressed air. 

Inspect 

1 

Inspect the intake manifold for the following fault conditions: 
• 

Damaged sealing and mating surfaces. 

• 

Damaged lower intake manifold gasket. 

• 

Damage or excessive debris on the threaded and through holes. 

• 

Cracks or damage to the intake manifold body. 

Engine Mechanical – V6 

Page 6A1–74 

 

N O T E  

If the lower intake manifold is cracked or 
damaged, it must be replaced. No welding or 
patching of the intake manifold should be 
performed. 

2 

Place a straight edge (1) across the upper intake 
manifold sealing surface (2). 

3 

Using a feeler gauge (3), measure the clearance 
between the manifold and the straight edge. 

4 

If the clearance between the upper intake manifold 
sealing surface and the straight edge exceeds the 
specified maximum warpage, replace the manifold. 

 

 

 

Upper manifold maximum 
warpage ............................................................ 0.05 mm 

Figure 6A1 – 54 

5 

Place a straight edge (1) across the lower intake 
manifold sealing surface (2). 

6 

Using a feeler gauge (3), measure the clearance 
between the manifold and the straight edge. 

7 

If the clearance between the lower intake manifold 
sealing surface and the straight edge exceeds the 
specified maximum warpage, replace the manifold. 

 

 

Lower manifold maximum 
warpage ............................................................ 0.05 mm 

Figure 6A1 – 55 

Reassemble 

Reassembly of the upper to lower intake manifold is the reverse of the disassembly procedure noting the following: 

1 

Ensure that both the manifolds have been cleaned and inspected. 

2 

Ensure that the warpage of the mating surfaces is within tolerances. 

3 

New upper to lower intake manifold gaskets must be used. 

4 

Do not tighten the intake manifold to lower intake manifold attaching bolt at this stage. The intake manifold 
attaching bolts must be tightened at the specified sequence during the reinstallation procedure. 

Reinstall 

Reinstallation of the upper intake manifold and the upper and lower intake manifold assembly is the reverse of the 
removal procedure, noting the following: 

1 

Install the EVAP hose to the clip attached to the lower intake manifold. 

2 

Only new gaskets are to be fitted between the upper and lower intake manifolds. 

3 

If undamaged, the lower intake manifold to cylinder head gasket may be re-used, however its replacement is 
strongly recommended. 

Engine Mechanical – V6 

Page 6A1–75 

 

CAUTION

 

Tighten the intake manifold bolts in a circular 
pattern starting at the centre bolt and moving 
outward. 

4 

Ensure that all fasteners are tightened to the correct torque specification. 

Upper intake manifold to lower intake 
manifold attaching bolt torque specification .......23.0 Nm 

Upper intake manifold to cylinder 
head attaching bolt torque specification.............23.0 Nm 

Lower intake manifold to cylinder 
head attaching bolt torque specification.............23.0 Nm 

Fuel injector wiring harness bracket 
attaching bolt torque specification........................9.0 Nm 

 

Incorrect wiring connector installation may 
cause component malfunction or component 
damage. 

5 

Ensure all wiring connectors are fully engaged and if applicable, locked in place. 

6 

Ensure all wiring harnesses are correctly routed and attached securely in their retaining clips. 

7 

Ensure that all hoses and pipes are routed correctly and that any retaining clips are correctly installed. 

8 

After installation pull on any quick connect fittings to check that each is correctly installed. 

9 

Start and run the engine to check for correct operation. 

3.11  Exhaust Manifold Assembly 

Remove 

 

Allow the engine to cool before commencing. 

 

Disconnection of the battery affects certain 
vehicle electronic systems, refer to 1.1 

 

WARNING, CAUTION and NOTES before 
disconnecting the battery. 

1 

Disconnect the battery negative terminal. 

Engine Mechanical – V6 

Page 6A1–76 

 

2 

Remove the oxygen sensor harness connector (1) 
from the retaining bracket. 

3 

Disconnect the oxygen sensor wiring harness 
connector from the engine wiring harness connector  
(2). 

4 

Unclip the oxygen sensor wiring harness retaining clip 
and move aside. 

5 

For the left-hand side: 

Remove the oil level indicator tube. 

6 

Raise the front of the vehicle and place on stands, 
refer to 0A General Information. 

7 

Working from under the vehicle, remove the two 
exhaust manifold to exhaust pipe flange nuts, refer to 
6F Exhaust System - V6 - V6. 

Figure 6A1 – 56 

8 

Remove the three bolts attaching the exhaust 
manifold outer heat shield (1) to the exhaust manifold 
(2). 

 

Figure 6A1 – 57 

9 

Progressively loosen the seven exhaust manifold 
attaching bolts (2), working from the outside to the 
centre and then remove the bolts. 

10 

Manoeuvre the exhaust manifold (3), away from the 
cylinder head. 

11 

Remove and discard the exhaust manifold to cylinder 
head gasket. 

 

 

 

Figure 6A1 – 58