Isuzu 4JA1 Workshop Manual page 346

6E-92 Engine Control System (4JH1)
Step
5 1. Remove the fuel hose that connects to the fuel
injection pump suction side.
2. Remove the fuel pipe connector that connects to
the fuel injection pump suction side.
3. Inspect the eye bolt for any type of restriction or
collapsed gauze filter.
Notice: If any type of restriction found, check for a
condition that causes contaminated fuel, such as the
customer is using an aftermarket fuel filter or
extended maintenance interval.Also inspect fuel
waxing or icing that is caused by an incorrect fuel
type used in winter season or water intrusion in the
fuel system.
4. Repair or replace as necessary.
Did you find and correct the condition?
6 1. Disconnect the fuel hose that connects to the
fuel injection pump suction side. In order to
measure the discharged fuel amount, put the
hose into a bottle or a container.
2. Pump the priming pump on the fuel filter.
Notice: If there is a leak on the suction side of the
fuel system, the fuel from the disconnected hose will
not flow out sufficiently and fuel leakage may occur.
Also if there is a restriction on the suction side of the
fuel system, the fuel from the disconnected hose will
not flow out sufficiently that is most likely caused by
clogged fuel filter or kinked fuel hose or pipe.
3. Draw fuel from the fuel tank at the fuel line (as
close to the fuel tank as possible) going to the
fuel pickup tube to verify a clean stream of fuel
comes out (use the hand-held vacuum pump 5-
8840-0279-0/J-23738-A with a clear hose or
equivalent). This will ensure the fuel pickup tube
is not cracked drawing air into the fuel line.
4. Repair any fuel system leaks and restrictions as
necessary.
Did you find and correct the condition?
Action Value(s) Yes

Go to Step 9

Go to Step 9
No
Go to Step 6
Go to Step 7