Isuzu KB P190. Manual - part 892

Engine Management – V6 – Service Operations 

Page 6C1-3–44 

 

3 

Disconnect the wiring harness connector (1) from the 
knock sensor (2). 

Figure 6C1-3 – 59 

 

4 

Remove the bolt (1) attaching the knock sensor (2) to 
the engine block, and remove the knock sensor. 

Figure 6C1-3 – 60 

Reinstall 

Reinstallation of the knock sensor is the reverse of the removal procedure, noting the following: 

1 

Ensure the knock sensor mounting surface is flat and free of any dirt, oxidisation, etc. 

Engine Management – V6 – Service Operations 

Page 6C1-3–45 

 

 

Ensure the knock sensor is fully seated 
before tightening the attaching bolt. 

Do not over-tighten the attaching bolt as 
incorrect operation of the knock sensor may 
result. 

2 

Reinstall the knock sensor and bolt (1). Align the 
knock sensor so that it is parallel to the engine oil pan 
mounting surface (2), ± 3° (3). 

3 

Tighten the knock sensor bolt to the correct torque 
specification. 

Knock sensor attaching bolt 
torque specification .................................21.0 – 25.0 Nm 

4 

Road test the vehicle and check for correct operation.

Figure 6C1-3 – 61 

2.20  Mass Air Flow Sensor  

The intake air temperature (IAT) sensor is part of the mass air flow (MAF) Sensor. For the IAT sensor test procedure 
refer to 2.17 

Intake Air Temperature Sensor. 

Handling Precautions 

 

Under no circumstances should the MAF 
sensor retaining screws (1) be loosened or 
removed as the MAF will become 
unserviceable and will require replacement. 

 

Figure 6C1-3 – 62 

Remove  

1 

Turn the ignition switch off. 

Engine Management – V6 – Service Operations 

Page 6C1-3–46 

 

2 

Disconnect the wiring harness connector (1) from the 
MAF sensor. 

3 

Remove the air intake duct, refer to 2.16 

Intake 

Air Duct Assembly. 

 

Figure 6C1-3 – 63 

5 

Remove the nut (1), two places, attaching the MAF 
sensor (2) to the upper air cleaner housing (3). 

6 

Position the flexible air intake duct away from the MAF 
sensor and remove the MAF sensor. 

N O T E  

The MAF sensor seal (4) is part of the air cleaner 
upper housing and is not serviced as a separate 
item. 

Figure 6C1-3 – 64 

Reinstall 

Reinstallation of the mass air flow (MAF) sensor is the reverse of the removal procedure, noting the following: 

 

Care must be taken not to over tighten the 
MAF sensor attaching nuts. Over tightening 
the nuts may cause damage to the MAF 
sensor seal and allow unfiltered air to enter 
the air intake system. 

1 

Tighten the MAF sensor nuts to the correct torque specification. 

Mass air flow sensor attaching nut 
torque specification .....................................1.8 – 2.2 Nm 

2 

Tighten the air intake duct retaining clamp screw to the correct torque specification. 

Air intake duct retaining clamp 
torque specification .....................................1.8 – 2.5 Nm 

3 

Start the engine and check for any air leaks between the air intake duct, the MAF and the upper air cleaner housing. 

4 

Road test the vehicle and check for correct operation, taking particular note that no air leaks are evident. 

Engine Management – V6 – Service Operations 

Page 6C1-3–47 

 

2.21  Schrader Valve – Fuel Pressure Gauge 

Connection Point 

 

If the Schrader valve is to be removed but not 
replaced immediately, it is advisable to 
disconnect the battery to avoid possible fuel 
discharge if an accidental attempt is made to 
start the engine.  

Disconnection of the battery affects vehicle 
electronic systems. Refer to 6D1-3 Battery – 
V6 before disconnecting the battery. 

Remove 

1 

Depressurise the fuel system, refer to 6C Fuel System - V6. 

2 

Turn the ignition off. 

 

A small amount of fuel may be released when 
servicing the fuel pressure test point. To 
reduce the chance of personal injury, cover 
the fuel pressure test point with a shop towel 
to absorb any fuel spillage when the Schrader 
valve sealing cap and Schrader valve are 
removed. After the procedure, place the towel 
in an approved container for disposal. 

3 

Remove the Schrader valve sealing cap (1). 

4 

Remove the Schrader valve (2) using a standard valve 
core removal tool.  

Figure 6C1-3 – 65 

Reinstall 

Reinstallation of the Schrader valve is the reverse of the removal procedure, noting the following: 

1 

Inspect the fuel rail and quick connect fitting for leaks, refer to 6C Fuel System - V6. 

2 

Road test the vehicle and check for correct operation.