Isuzu 2000 Trooper Workshop Manual page 1129

6E–260
TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Step
1 Was the "On-Board Diagnostic (OBD) System Check"
performed?
2 1. Start the engine. Run the engine at idle.
2. Review and record the Tech 2 Freeze Frame data.
3. Operate the vehicle to duplicate the conditions
present when the DTC was set (as defined by the
Freeze Frame data).
4. Monitor the Tech 2 "Misfire Cur. #" display for each
cylinder.
Is "Misfire Cur. #" display increasing for any cylinder
(indicating a misfire currently occurring)?
3 1. Visually and physically inspect the vacuum hoses
for splits, kinks, and improper connections.
2. If a problem is found, repair or replace the vacuum
hoses as necessary.
Did your inspection reveal a problem?
4 1. Visually and physically inspect the following areas
for vacuum leaks:
D
The intake manifold
D
The injector O-rings
D
The EGR adapter
D
The EGR feed pipes
D
ION Sensing Module
2. If a problem is found, repair the vacuum leak as
necessary.
Did your inspection reveal a vacuum leak?
5 1. Visually and physically inspect the crankcase
ventilation valve for improper installation or
damaged grommet.
2. If a problem is found, repair as necessary (refer to
Crankcase Ventilation System ).
Did your inspection reveal a problem?
6 1. Inspect the MAF sensor inlet screen for damage or
for the presence of foreign objects that may partially
block the air flow sample through the MAF sensor.
2. If a problem is found, repair or replace the MAF
sensor as necessary.
Did your inspection of the MAF sensor reveal a
condition requiring repair or replacement?
7 1. Remove the EGR valve and visually/physically
inspect the valve to ensure that the pintle is not
sticking partially open. Also, inspect the EGR valve
pintle and seat for carbon deposits or burrs that may
interfere with the pintle closing completely.
2. If a problem is found, clean the EGR valve pintle and
seat or replace the EGR valve as necessary.
Did your inspection reveal a problem?
DTC P0300 – Engine Misfire Detected
Action Value(s) Yes
— Go to Step 2
— Go to Step 3
— Verify repair
— Verify repair
— Verify repair
— Verify repair
— Verify repair
No
Go to OBD
System
Check
Refer to
Diagnostic
Aids
Go to Step 4
Go to Step 5
Go to Step 6
Go to Step 7
Go to Step 8