Isuzu 1999 RODEO Workshop Manual page 955

6E1–328 RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION
DTC P1171 – Fuel System Lean During Acceleration
Step
1 Was the "On–Board Diagnostic (OBD) System Check"
performed?
2 Are any component–related Diagnostic Trouble Codes
set?
3 1. Check the vehicle's fuel tank for an adequate
amount of fuel.
2. Add fuel to the vehicle's fuel tank if the tank is almost
empty.
Was fuel added to the vehicle's fuel tank?
4 1. Using a Tech 2, observe HO2S 1 voltage while
running warm engine(75°C–95°C [167°F–203°F])
at 1200 RPM.
2. HO2S 1 voltage should vary within the specified
range.
Does the voltage toggle back and forth within the
specified range?
5 1. Disconnect the fuel pump relay and crank the
engine to relieve the fuel pressure.
2. Install the fuel pressure gauge.
3. Start the engine and idle at normal operating
temperature.
4. Disconnect the vacuum line going to the fuel
pressure regulator.
With the engine running, is the fuel pressure within the
specified range?
6 Check for restricted fuel lines or restricted in–line filter.
Was a problem found?
7 1. Ignition OFF.
2. Ignition ON, engine OFF.
3. Using a Tech 2, enable the fuel pump to operate.
4. Using pliers, slowly close the return line (do not
exceed the first specified value).
Using the pliers, can the fuel pressure be manipulated
to exceed the second specified value?
8 Check for:
f
Faulty fuel pump
f
Restricted fuel pump strainer (sock)
f
Incorrect fuel pump
f
Incorrect fuel being used
f
Hot fuel
Action Value(s) Yes
— Go to Step 2
Go to
component
— DTC charts
— Go to Step 4
Go to
Diagnostic
100– 900 mV Aids
Go to OBD
System
Check
284– 325 kPa
— Verify repair
Go to
414 kPa 325
Diagnostic
Aids
kPa
— Verify repair
No
Go to OBD
System
Check
Go to Step 3
Go to Step 5
Go to Step 5
Go to Step 6
Go to Step 7
Go to Step 8
—