Isuzu 4JA1 Workshop Manual page 302

6E-48 Engine Control System (4JH1)
Step
4 1. Inspect the high pressure side between the fuel
injection pump and the fuel injection nozzles for
fuel leakage. The following components may
contain an external leak.
•
Fuel injection pump
•
Fuel injection pump control unit (PCU)
•
Fuel injection solenoid valve
•
Timing control valve (TCV)
•
Constant pressure valve (CPV)
•
Fuel pipe between the fuel injection pump
and fuel injection nozzles
•
Each fuel pipe sleeve nuts
•
Each fuel pipe connectors
•
Each gaskets
Notice: Fuel may leak into the engine from the fuel
injection pump. In such case, the engine oil level will
rise. Inspect for fuel leakage into the engine oil.
2. Repair any fuel system leaks as necessary.
Did you find and correct the condition?
5 1. Turn OFF the ignition.
2. Check the fuel system line connections between
the fuel tank and the fuel injection pump for
tightness and all fuel hoses for cuts, cracks and
for the use of proper clamps.
3. Pump the priming pump on the fuel filter until it
becomes firm. If there is a leak on the suction
side of the fuel system between the priming
pump and the fuel injection pump, the priming
pump will not build up sufficient firmness and fuel
leakage may occur.
4. Repair or replace as necessary.
Did you find and correct the condition?
6 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?
Action Value(s) Yes

Go to Step 10

Go to Step 10

Go to Step 10
No
Go to Step 5
Go to Step 6
Go to Step 7