Fuel System Check - Isuzu 4LE2 Workshop Manual

15C-4 Functional Inspection (4LE2)
1. Fuel system check description of function
The fuel system consists of the fuel tank, fuel filter,
supply pump, common rail (fuel rail), and injectors, with
each component being connected by the fuel pipe.
2. Fuel system check inspection
Inspection when there may be a malfunction in the fuel
system
1. Inspect the fuel quality.
The appropriate fuel should be used.
2. Check the fuel amount.
The amount supplied must be sufficient.
3. Inspect the fuel discharge of the supply pump.
The fuel discharge should be normal and there should be
no air intrusion.
4. Check whether any filter other than a genuine fuel
filter, pre-filter, and electromagnetic pump filter has
been added to the fuel pipe of the machine.
Note：
・ An additional filter increases the fuel
resistance and may cause DTC P0093 to be
detected.
5. If a filter has been added, remove it.
6. Inspect the main fuel filter, the pre-fuel filter, and the
electromagnetic pump filter.
・There should be no excessive contamination or
clogging.
・There should be no air intrusion.
7. If a problem is found, clean or replace.
8. Inspect the fuel pipe.
There should be no damage, clogging, or poor
connections.
9. If a problem is found, repair or replace.
10. Inspect the fuel tank.
・There should be no intrusion of dirt.
・There should be no disconnection or damage to the fuel
supply pipe.
・There should be no crushing or damage to the tank.
・There should be no incorrect piping of the fuel pipe.
・There should be no clogging in the fuel filler.
・There should be no water in the tank.
11. If a problem is found, repair or replace the fuel tank.
Remove the air.
12. Remove the air.

Fuel system check