removing the rocker cover and noting when the
valves of No 4 cylinder are rocking, ie the inlet
valve just opening and the exhaust valve just
closing. If this check is not made, it is all too
easy to set the timing 180º out, as both No 1
and No 4 pistons approach TDC at the same
time, but only one is on the compression
stroke. On manual transmission models, the
engine can be turned over quite easily by
engaging top gear and moving the car
forwards. This should only be done on level
ground; and make sure that the car cannot run
away! An alternative method, and the method
that should be used on automatic transmission
models, is to press the fan belt midway
between the water pump pulley and dynamo or
alternator pulley and then turn the fan blades.
8 Continue turning the engine, in the correct
direction of rotation, until the appropriate
timing mark on the flywheel or torque
converter is in line with the pointer on the
housing.
9 The distributor rotor arm should now be
pointing towards the No 1 spark plug HT lead
segment in the distributor cap. Temporarily
place the cap in position to verify this if
necessary.
10 With the engine set in the correct position
and the rotor arm pointing towards the
appropriate segment, turn the knurled vernier
adjustment wheel, on the distributor (where
applicable), until approximately half the marks
on the vacuum unit timing scale are visible.
11 Next slacken the distributor clamp plate
pinch bolt and turn the distributor body
clockwise until the points are just beginning to
open. If they are already open, turn the
distributor body anti-clockwise until they are
fully closed, then turn it clockwise until they
just begin to open. Now tighten the pinch bolt.
If the distributor incorporates a knurled vernier
adjustment wheel on the vacuum unit a very
fine degree of accuracy can be obtained.
Turning the wheel in the direction “A”
stamped on the vacuum unit advances the
timing, and turning it towards “R” retards it.
Eleven clicks of the wheel represents 1º of
timing movement and each graduation of the
vernier scale is equal to approximately 5º of
timing movement.
12 Difficulty will probably be experienced in
determining exactly when the contact breaker
points open, so the following method can be
used. Connect a 12 volt bulb in parallel with
the contact breaker points (one lead to earth
and the other to the distributor (-) low tension
terminal on the coil). With the ignition switch
on the bulb will light as the points open. The
distributor body should be turned as in
paragraph 11 until the point is reached where
the bulb just lights up.
13 To adjust the ignition timing using a
stroboscopic timing light, first connect the
light in accordance with the manufacturer’s
instructions.
14 Start the engine and allow it to reach
normal running temperature.
15 Refer to the Specifications for the
appropriate ignition timing setting and the
corresponding engine speed.
16 Disconnect the vacuum advance pipe
from the distributor and adjust the engine
speed to that specified (see Chapter 4A).
17 Remove the inspection cover from the
flywheel or converter housing and shine the
light beam into the aperture. Use a mirror to
deflect the beam onto the flywheel or torque
converter. On later models there is an
additional and more easily visible timing scale
on the timing cover, together with a notch or
pointer on the crankshaft pulley
18 Turn the knurled adjustment wheel or
slacken the distributor clamp or pinch bolt
and rotate the distributor body until the timing
marks and pointer appear stationary and
directly in line with each other.
19 Tighten the clamp or pinch bolt, recheck
that the timing is still correct, and then
reconnect the vacuum pipe. After
disconnecting the timing light, reset the engine
idling speed to that specified (Chapter 4A).
20 Whichever method has been used to set
the ignition timing, a thorough road test
should be carried out to ensure that the
engine performance is satisfactory under all
engine load conditions. As a general guide,
the timing is correct if very slight “pinking” can
be heard with the engine labouring (ie at the
point where you would normally change to a
lower gear). Any small corrections necessary
can be made during the road test using the
vernier adjustment wheel, or by turning the
distributor body very slightly in the required
direction.
Fuel injection models
21 While home mechanics with a timing light
and a good-quality tachometer may be able to
check the ignition timing, if it is found to be in
need of adjustment, the car must be taken to
a suitably-equipped Rover dealer;
adjustments can be made only by re-
programming the fuel injection/ignition system
ECU, using Rover diagnostic equipment con-
nected to the system by the diagnostic
connector. Note also that the timing and idle
speed are under ECU control and may,
therefore, vary significantly from the nominal
values given; without full equipment, any
check is therefore nothing more than a rough
guide.
14 Transmission-controlled
ignition advance - checking
and component renewal
2
Note: This procedure only applies to
carburettor models.
Checking
1 To check the operation of the system,
chock the front wheels, apply the handbrake
and start the engine.
2 Increase engine speed to approximately
2500 rpm.
3 Depress and hold the clutch pedal down
while selecting fourth gear.
4 With fourth gear selected, engine speed
should increase by 300 to 400 rpm.
5 Disengage fourth gear, release the clutch
pedal, and stop the engine.
6 If the system does not respond as
described, check the inhibitor switch
adjustment as described below.
Component renewal
Inhibitor switch
7 Chock the rear wheels then jack up the
front of the car and support it on axle stands
(see “Jacking and vehicle support”). Place the
gear lever in neutral.
8 Disconnect the electrical leads from the
inhibitor switch, located behind the
gearchange remote control housing.
Slacken the locknut securing the switch to its
mounting bracket then unscrew the switch
from the bracket.
9 Fit the switch to the mounting bracket and
adjust as follows before tightening the locknut
or reconnecting the leads.
10 Connect a self-powered test lamp to the
terminals of the inhibitor switch, and screw
the switch out of its mounting bracket until the
lamp lights.
11 Now screw the switch in until the lamp
goes out.
12 Screw the switch in a further one and one
half to two flats, then tighten the locknut.
13 Check that the lamp lights only when the
fourth gear is selected.
14 Remove the test lamp, reconnect the
electrical leads, and carry out the test
procedure previously described.
Solenoid valve
15 Pull the vacuum hoses from the solenoid
valve.
16 Disconnect the electrical leads.
17 Remove the mounting screw, noting the
earth lead, and remove the valve.
18 Refitting is the reverse sequence to
removal, ensuring that the earth lead is fitted
under the mounting bolt.
Ignition system 5B•17
5B
Turning the engine will be
easier if the spark plugs are
removed first - see Chapter 1.
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