
RENR9968-02 29
Testing and Adjusting Section
i02209818
Electronic Unit Injector - Test
SMCS Code: 1290-081
This procedure a ssists in identifying the cause for
an injector misfiring. Perform this procedure only
after p e rforming the Cylinder Cutout Tes t. Refer to
Troubleshooting, “Injector Solenoid Circuit-Test” for
more information.
1. Check for air in the fuel, if this procedure has not
already been performed. Refer to Testing and
Adjusting, “Air in Fuel - Test”.
Electrical shock hazard. The electronic unit injec-
tor system uses 90-120 volts.
2. Remove the valve c ov er and look for broken
parts. Repair any broken parts or replace any
broken parts that are found. Inspect all wiring for
the solenoids. Look for loose connections. Also
look for frayed wires or broken wires. Ensure
that the connector for the unit injector solenoid is
properly connected. Perform a pull test on each
of the wires. Inspect the posts of the solenoid
for arcing. If arcing is found, remove the cap
assembly. Clean the connecting posts. Reinstall
the cap assembly and tighten the solenoid nuts to
a torque of 2.50 ± 0.25 N·m (22 ± 2 lb in). Refer
to Disassembly and Assembly Manual, “ Electronic
Unit Injector - Install”.
3. Look for signs of fuel leakage. Investigate the
source of the leaking fuel. Remedy the cause of
the fuel leak.
4. Check the valve lash setting for the cylinder of
the sus pect unit injector. R efer to Tes tin g and
Adjusting, “Engine Valve Lash - Inspect/Adjust”.
5. Ensure that the bolt that holds the unit injector
is tightened to the proper torque. If necessary,
loosen the bolt that holds the unit injector and
tighten with the procedure from Specifications,
“Electronic Unit Injector Mechanism”.
6. Remove the suspect unit injector and check the
unit injector for signs of exposure to coolant.
Exposure to coolant will cause rust to form on
the injector. If the unit injector shows signs of
exposure to coolant, remove the injector sleeve
and inspect the inject or sleeve. Re p lace the
injector sleeve if the injector sleeve is damaged.
Check the unit injector for an excessive brown
discoloration that extends beyond the injector tip. If
excessive discoloration is found, check the quality
of the fuel. Refer to Testing and Adjusting, “Fuel
Quality - Test”. Replace the seals on the injector
and reinstall the injector. Refer to Disassembly
and Assembly Manual, “Electronic Unit Injector -
Install”. Also refer to Disassembly and Assembly
Manual, “Electronic Unit Injector Sleeve - Install”.
Inspect the injector for deposits of soot that are
above the surface of the seat of the injector.
Deposits of soot indicate combustion gas leakage.
The source of the leak should be found, and
the source of the leak should be remedied. The
injector will not need to be replaced if combustion
gas leakage w as the problem.
7. If the problem is not resolved, replace the suspect
injector with a new injector.
i02226500
Finding Top Center Position
for No. 1 Piston
SMCS Code: 1105-531
Ta b l e 2
Needed Tools
9S-9082 Engine Turning Tool 1
TheNo.1pistonatTopCenter(TC)onthe
compression stroke is the starting point of all timing
procedures.
Note: Some engines have two threaded holes in the
flywheel. These holes are in alignment with the holes
with plugs in the le ft and right front of the fl ywheel
housing. The two holes in the flywheel are at a
different distance from the center of the flywheel so
the timing bolt cannot be put in the wrong hole.