TROUBLESHOOTING WITHOUT A DIAGNOSTIC CODE - CONTINUED
Table 1. Engine Troubleshooting - Continued.
TEST OR INSPECTION
N OT E
Noise Coming from
Cylinder - Continued.
It is not necessary to swap the injector trim files for this temporary exchange
of two injectors. Injectors must be properly installed and adjusted for this
5. Use MSD to perform Cylinder Cutout
1. If misfire problem stays with the
suspect injector, replace the suspect
Temporarily swap suspect injector
injector and install new trim file for it
from the misfiring cylinder with an
(WP 0187 00). The other good injector
injector from a cylinder that is not
that was moved must first be returned
to its original position or its trim file
cylinder cutout test to determine
must be moved to its new location.
whether the misfire stays with the
2. If cylinder cutout test indicates the
suspect injector or with the original
misfire continues to be in the same
cylinder, the suspect injector is not the
problem. Return the injectors to their
original position or move the trim files
to the new location. Investigate other
possible causes of misfire for the
problem cylinder, check valve lash
(WP 0179 00).
3. If problem still exists, go to Test 6.
6. Remove valve cover (WP 0024 00) and Make any necessary repairs.
oil pan (WP 0181 00). Check for worn
cam lobes, lifters, or push rods for the
misfiring cylinder. Check for
1. Check vibration damper for damage
1. Replace worn or damaged parts and
(WP 0173 00).
tighten any loose bolts.
2. If problem still exists, go to Test 2.
2. Inspect engine mounts and brackets
1. Tighten loose bolts. If necessary,
(WP 0171 00) while engine is run
replace mounts (WP 0171 00).
through speed range.
2. If problem still exists, go to Test 3.
3. Check alignment and balance of engine Replace any suspect components.
1. Remove valve cover (WP 0024 00) and 1. If oil flow is restricted, unblock
Excessive Valve Lash.
check lubrication in valve
passages to valve train.
compartment. Ensure there is adequate 2. If problem still exists, go to Test 2.
engine oil flow in valve compartment.
Passages for engine oil must be clean.
2. Clean valve lash (WP 0179 00).
Adjust valve lash as necessary.
3. Remove valve cover (WP 0024 00) and If damaged, replace rocker arm shaft (WP
inspect valve train and cylinder head
0180 00) or cylinder head (WP 0172 00).
for obvious signs of damage.