Isuzu 2008MY N Series Workshop Manual page 241

1A-238 Engine Control System (4HK1)
Step
1. Inspect the fuel system line connections
between the fuel tank and the fuel supply
pump for tightness and all fuel hoses for cuts,
cracks and for the use of proper clamps.
8
2. Repair or replace as necessary.
Did you find and correct the condition?
1. Turn OFF the ignition.
2. Unclamp or unplug the fuel line from the
previous step and reconnect the fuel line (if
disconnected).
3. Start the engine and allow it to run for at least
1 minute.
9
4. Perform the Cylinder Balance Test with a scan
tool.
5. Command each injector OFF and verify an
engine speed change for each injector.
Is there an injector that does not change
engine speed when commanded OFF?
1. Turn OFF the ignition.
2. Disconnect
connector.
3. Inspect
connections and corrosion at the harness
connector of the FRP regulator (pins 1 and 2
of E-17).
4. Disconnect the ECM harness connector.
10
5. Inspect
connections and corrosion at the harness
connector of the ECM (pins 89, 97, 105 and
113 of E-12).
6. Test for high resistance on each circuit.
7. Repair the connection(s) or circuit(s) as
necessary.
Did you find and correct the condition?
1. Turn OFF the ignition.
2. Disconnect
connector.
3. Inspect
connections and corrosion at the harness
connector of the FRP sensor (pins 1, 2 and 3
of E-19).
4. Disconnect the ECM harness connector.
11
5. Inspect
connections and corrosion at the harness
connector of the ECM (pins 82, 87, 90 and
101 of E-12).
6. Test for high resistance on each circuit.
7. Repair the connection(s) or circuit(s) as
necessary.
Did you find and correct the condition?
Replace the fuel filter element. Refer to Fuel Filter
Element in Section 1D Engine Fuel .
12
Did you complete the replacement?
Action
the FRP regulator
for an intermittent,
for an intermittent,
the FRP sensor
for an intermittent,
for an intermittent,
Value(s)
—
—
harness
for poor
—
for poor
harness
for poor
—
for poor
—
Yes
Go to Step 17 Go to Step 10
Go to Step 14 Go to Step 16
Go to Step 17 Go to Step 15
Go to Step 17 Go to Step 13
Go to Step 17
No
—