Engine Tune-Up Procedures; Drive Belts; Vacuum Hoses And Fittings; Ignition System - Jeep 1987 Wrangler Workshop Manual

ENGINES
ENGINE TUNE-UP PROCEDURES
GENERAL INFORMATION
An engine tune-up is recommended every
48 OOO km (30,000 mi). A tune-up ensures
the engine is operating a s efficiently and
economically as it was designed to operate.
Also, it ensures that undesirable exhaust and
fuel system emission to the atmosphere are
within the limits defined by regulations.
For convenience, when performing a tune-up,
the necessary services are grouped together by
either major assembly or system.
DRIVE BELTS
Inspect the belts for defects such as fraying and
cracks.
Test the belt tension. Belt tension testing,
adjustment, arrangements and tension specifi-
cations are listed in the Cooling Systems
section.
W A C U U M HOSES AND FITTINGS
Inspect the vacuum hose fittings for looseness
and corrosion. Inspect the hoses for brittleness
and cracks.
Thoroughly inspect the hose ends that are
slipped onto nipples.
Engine performance may be adversely affected
by air leaks into such unlikely places as the
heater and air conditioner control vacuum hoses
or the power brake booster vacuum hose.
IGNITION
SYSTEM
Spark Plugs
Remove and examine the spark plugs for
burned electrodes and fouled, cracked or
broken porcelain insulators.
Retain the plugs arranged in the order in which
they were removed from the engine. A specific
plug displaying an abnormal condition indicates
that a problem exists in the cylinder from which it
was removed.
Replace the plugs at the interval recommended
in the Engine Maintenance Schedule. Plugs with
less engine mileage may be cleaned and reused
in some circumstances. Refer to Spark Plug
Condition.
After cleaning, file the center electrode tip flat
with a point file. Adjust the gap (SEPARATION)
between the electrodes to the specified
dimension.
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