DaimlerChrysler LH New Yorker 1994, Electronic Service Manual

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tinuous bead approximately 3 mm (0.120 inch.) in
diameter. All mounting holes must be circled. For
corner sealing, a 3.17 or 6.35 mm (1/8 or 1/4 inch.)
drop is placed in the center of the gasket contact
area. Uncured sealant may be removed with a shop
towel. Components should be torqued in place while
the sealant is still wet to the touch (within 10 min-
utes). The usage of a locating dowel is recommended
during assembly to prevent smearing of material off
location.
ENGINE PERFORMANCE
If a loss of performance is noticed, ignition timing
should be checked. If ignition timing is retarded by
9, 18 or 27° indicating 1, 2 or 3 (timing belt) teeth
may have skipped. The camshaft and crankshaft
timing should be checked. Refer to Engine Timing
Sprockets and Oil Seals of the Engine Section.
To provide best vehicle performance and lowest
vehicle emissions, it is most important that the
tune-up be done accurately. Use the specifications
listed on the Vehicle Emission Control Information
label found in the engine compartment.
(1) Test cranking amperage draw. See Starting
Motor Cranking Amperage Draw Electrical Section
of this manual.
(2) Tighten the intake manifold bolts to specifica-
tions.
(3) Perform cylinder compression test.
(a) Check engine oil level and add oil if neces-
sary.
(b) Drive the vehicle until engine reaches nor-
mal operating temperature.
(c) Select a route free from traffic and other
forms of congestion, observe all traffic laws, and
accelerate through the gears several times briskly.
CAUTION: Do not overspeed the engine. The higher
engine speed may help clean out valve seat deposits
which can prevent accurate compression readings.
(d) Remove all spark plugs from engine. As
spark plugs are being removed, check electrodes
for abnormal firing indicators fouled, hot, oily, etc.
Record cylinder number of spark plug for future
reference.
(e) Disconnect the coil connector for Direct Igni-
tion System (DIS).
(f) Be sure throttle blade is fully open during the
compression check.
(g) Insert compression gage adaptor into the #1
spark plug hole in cylinder head. Crank engine
until maximum pressure is reached on gage.
Record this pressure as #1 cylinder pressure.
(h) Repeat Step G for all remaining cylinders.
(i) Compression
should not be less than
(689kPa) 100 psi and not vary more than 25 per-
cent from cylinder to cylinder.
(j) If one or more cylinders have abnormally low
compression pressures, repeat steps 4b through
4h.
(k) If the same cylinder or cylinders repeat an
abnormally low reading on the second compression
test, it could indicate the existence of a problem in
the cylinder in question.
The recommended compression pressures are
to be used only as a guide to diagnosing engine
problems. An engine should not be disas-
sembled to determine the cause of low com-
pression unless some malfunction is present.
(4) Clean or replace spark plugs as necessary and
adjust gap as specified in Electrical Group 8. Tighten
to specifications.
(5) Test resistance of spark plug cables. Refer to
Ignition System Secondary Circuit Inspection Elec-
trical Section Group 8.
(6) Inspect the primary wire. Test coil output volt-
age, primary and secondary resistance. Replace
parts as necessary. Refer to Ignition System and
make necessary adjustment.
(7) Test fuel pump for pressure and vacuum. Refer
to Fuel System Group 14, Specifications.
(8) The air filter elements should be replaced as
specified in Lubrication and Maintenance, Group 0.
(9) Inspect crankcase ventilation system as out-
lined in Lubrication and Maintenance, Group 0. For
emission controls see Emission Controls Group 25
for service procedures.
(10) Inspect and adjust accessory belt drives refer-
ring to Accessory Belt Drive in Cooling System,
Group 7 for proper adjustments.
(11) Road test vehicle as a final test.
HONING CYLINDER BORES
Before honing, stuff plenty of clean shop towels
under the bores, over the crankshaft to keep abra-
sive materials from entering crankcase area.
(1) Used carefully, the cylinder bore resizing hone
C-823 equipped with 220 grit stones, is the best tool
for this job. In addition to deglazing, it will reduce
taper and out-of-round as well as removing light
scuffing, scoring or scratches. Usually a few strokes
will clean up a bore and maintain the required lim-
its.
(2) Deglazing of the cylinder walls may be done
using a cylinder surfacing hone, Tool C-3501,
equipped with 280 grit stones (C-3501-3810) if the
cylinder bore is straight and round. 20-60 strokes
depending on the bore condition will be sufficient to
provide a satisfactory surface. Inspect cylinder walls
after each 20 strokes. Using a light honing oil avail-
able from major oil distributors. Do not use engine
or transmission oil, mineral spirits or kero-
sene.
(3) Honing should be done by moving the hone up
and down fast enough to get a cross-hatch pattern.
9 - 2 ENGINE