remote start FORD MONDEO 1993 Service Repair Manual

specifications were available from Ford, but a
typical reading would be in excess of 12 bars.
All cylinders should produce very similar
pressures; any difference greater than 10%
indicates the existence of a fault. Note that the
compression should build up quickly in a
healthy engine; low compression on the first
stroke, followed by gradually-increasing
pressure on successive strokes, indicates worn
piston rings. A low compression reading on the
first stroke, which does not build up during
successive strokes, indicates leaking valves or a
blown head gasket (a cracked head could also
be the cause). Deposits on the undersides of the
valve heads can also cause low compression.
8If the pressure in any cylinder is
considerably lower than the others, introduce
a teaspoonful of clean oil into that cylinder
through its spark plug hole, and repeat the
test.
9If the addition of oil temporarily improves
the compression pressure, this indicates that
bore or piston wear is responsible for the
pressure loss. No improvement suggests that
leaking or burnt valves, or a blown head
gasket, may be to blame.
10A low reading from two adjacent cylinders
is almost certainly due to the head gasket
having blown between them; the presence of
coolant in the engine oil will confirm this.
11If one cylinder is about 20 percent lower
than the others and the engine has a slightly
rough idle, a worn camshaft lobe or faulty
hydraulic tappet could be the cause.
12If the compression is unusually high, the
combustion chambers are probably coated
with carbon deposits. If this is the case, the
cylinder head should be removed and
decarbonised.
13On completion of the test, refit the spark
plugs, then reconnect the ignition system and
fuel pump.
General
1Top Dead Centre (TDC) is the highest point
in its travel up-and-down its cylinder bore
that each piston reaches as the crankshaftrotates. While each piston reaches TDC both
at the top of the compression stroke and
again at the top of the exhaust stroke, for the
purpose of timing the engine, TDC refers to
the piston position (usually No 1 piston) at the
top of its compression stroke.
2It is useful for several servicing procedures
to be able to position the engine at TDC.
3No 1 piston and cylinder are at the right-
hand (timing belt) end of the engine (right-
and left-hand are always quoted as seen from
the driver’s seat). Note that the crankshaft
rotates clockwise when viewed from the
right-hand side of the vehicle.
Locating TDC
4Remove all the spark plugs (Chapter 1).
5Disconnect both battery leads - see
Chapter 5, Section 1 - unless the starter
motor is to be used to turn the engine.
6Apply the handbrake and ensure that the
transmission is in neutral, then jack up the
front right-hand side of the vehicle and
support on an axle stand. Remove the
roadwheel.
7Remove the auxiliary drivebelt cover (see
Chapter 1) to expose the crankshaft pulley
and timing marks.
8It is best to rotate the crankshaft using a
spanner applied to the crankshaft pulley bolt;
however, it is possible also to use the starter
motor (switched on either by an assistant
using the ignition key, or by using a remote
starter switch) to bring the engine close to
TDC, then finish with a spanner. If the starter
is used, be sure to disconnect the battery
leads immediately it is no longer required.
9Note the two pairs of notches in the inner
and outer rims of the crankshaft pulley. In the
normal direction of crankshaft rotation
(clockwise, seen from the right-hand side of the
vehicle) the first pair of notches are irrelevant to
the vehicles covered in this manual, while the
second pair indicate TDC when aligned with
the rear edge of the raised mark on the sump.
Rotate the crankshaft clockwise until the
second pair of notches align with the edge of
the sump mark; use a straight edge extended
out from the sump if greater accuracy is
required (see illustrations).10Nos 1 and 4 cylinders are now at TDC,
one of them on the compression stroke.
Remove the oil filler cap; if No 4 cylinder
exhaust cam lobe is pointing to the rear of the
vehicle and slightly downwards, it is No 1
cylinder that is correctly positioned. If the
lobe is pointing horizontally forwards, rotate
the crankshaft one full turn (360°) clockwise
until the pulley notches align again, and the
lobe is pointing to the rear and slightly down.
No 1 cylinder will then be at TDC on the
compression stroke.
11Once No 1 cylinder has been positioned
at TDC on the compression stroke, TDC for
any of the other cylinders can then be located
by rotating the crankshaft clockwise 180° at a
time and following the firing order (see
Specifications).
12An alternative method of locating TDC is
to remove the cylinder head cover (see
Section 5) and to rotate the crankshaft
(clockwise, as described in paragraph 8
above) until the inlet valves for the cylinder
concerned have opened and just closed
again. Insert a length of wooden dowel
(approximately 150 mm/6 in long) or similar
into the spark plug hole until it rests on the
piston crown, and slowly further rotate the
crankshaft (taking care not to allow the dowel
to be trapped in the cylinder) until the dowel
stops rising - the piston is now at the top of
its compression stroke, and the dowel can be
removed.
13There is a “dead” area around TDC (as
the piston stops rising, pauses and then
begins to descend) which makes difficult the
exact location of TDC by this method; if
accuracy is required, either establish carefully
the exact mid-point of the dead area, or refer
to the timing marks (paragraph 9 above).
1Unplug the two electrical connectors and
disconnect the vacuum hose (where fitted),
then remove the air cleaner assembly cover
with the air mass meter, the resonator and the
plenum chamber (see Chapter 4).
2Disconnect the accelerator cable from the
5 Cylinder head cover-
removal and refitting
4 Top Dead Centre (TDC) for
No 1 piston - locating
2A•6 In-car engine repair procedures
4.9A Do not use crankshaft pulley’s first
pair of notches “A” - align second pair of
notches “B” with raised rib on sump “C” . . .4.9B . . . using a straight edge extended
out from the sump (arrowed) if greater
accuracy is required5.4 Disconnecting crankcase breather
hose from cylinder head cover union
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