Precautions for Removing and Reinstalling Parts


The common-rail system consists of precision parts and uses highly pressurized fuel. Therefore, extreme care must be taken to ensure that foreign matter does not enter the system.

1. Thoroughly clean and wash the work area to remove any dirt or rust before disassembling any parts in order to prevent the interior of the fuel system from becoming contaminated during disassembly.

2. Place the parts in plastic bags to prevent the entry of foreign matter and to protect the sealing surfaces from damage during storage.

3. Thoroughly clean the parts before assembly, making sure that their sealing surfaces are free of foreign matter such as dust or cutting chips.

Injection Pipe Installation

Observe the precautions given below in order to install the injection pipes.

1. To reinstall a removed part to its original position, wash the injection pipes and make sure that their sealing surfaces are free of foreign matter or cuts before installing the pipes.

2. Because the injection pipes cannot accommodate excessive alignment changes, changes in the combination of the installed parts must be avoided. (The pipes should not be reused on a different engine, and the cylinder order of the injectors should not be altered.)

3. For the same reason, also replace the pipes with new parts if a part that affects the alignment must be replaced. Instances in which the injection pipes must be

replaced :

When injectors or the common-rail is replaced.

Instance in which the fuel inlet pipe must be replaced :

When the supply pump or the common-rail is replaced.


Pipe Fitting Conditions

The common-rail EFI-diesel system maintains fuel at an extremely high pressure. The areas in which the pipes and parts are joined use a type of pipe union that is sealed by deforming its sealing surface. For this reason, if either the injector, common-rail, or the supply pump is replaced, the pipes must also be replaced because their matching surfaces have been changed. Failure to replace the pipe will cause a fuel leak. Fuel Leak Inspection

Check for fuel leaks after tightening the union. Use the active mode of a hand-held tester to increase the fuel pressure in order to check for fuel leaks. Before starting the engine, first inspect the assembly conditions. Then, operate the engine at idle to check for fuel leaks. Finally, perform an active test. To perform an active test, select the Fuel Leak Test in the active test mode of a hand-held tester. If a hand-held tester is unavailable, quickly depress the accelerator pedal entirely to accelerate to the maximum engine speed, and maintain that speed for 2 seconds. Repeat this operation several times.

SCV Inspection

Inspect the SCV as Follows:

Disconnect the SCV1and SCV2 connectors. Using an ohmmeter, measure the resistance between terminals as shown. Specified Resistance:1.5-1.7 at 20

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