1988 CITROEN CX Wheel

Raise the R.H side of the vehicle and support it on
stands.
Disconnect the negative lead from the battery
Engage the highest gear. Using the road wheel, turn
the engine.
Set No. I cylinder to the initial timing point, Fig. I.
(look into the oil filler hole)
- Bring cylinder No. 1 valves into the rocking position
by rotating the engine one turn clockwise.
- Marks- and- should be aligned.
Remove:
- the road wheel,
- the wheelarch lining,
- the belt upper protection cover.
Loosen:
- the injection pump drrvrng pinion nut,
- the belt tensioner nut,
- compress the spring of the tensioner.
Remove:
- the pinion nut,
- the injection pump driving belt. MANDATORY: TO AVOID THE PUMP BEING
DAMAGED INTERNALLY WHEN REMOVING
THE DRIVING PINION, PULLER REF. H AND ITS
NUT J FROM TOOL BOX 6028.T MUST BE
USED.
Fit the nut and clamp of tool 6028.T, Fig. II.
Slacken the nut of tool 6028.T until the injection
pump drive shaft starts moving.
Disconnect the electrical STOP solenoid
Uncouple:
- the accelerator cable,
- the fast idling cable,
- the fuel supply pipe,
- the fuel return pipe.
DPC injection pump, Fig. ill:
Disconnect from the overfuelling circuit:
- the diesel fuel return pipe (21,
- the air pipe (I 1.
Push the diesel fuel filter to one side
Remove:
- the spring,
- the injectors sets of feed pipes,
- the pump fixing nuts (3) Fig. IV.
by means of a 73 mm A/F open spanner
and a 6 mm hexagon Allen key.

REMOVING/REFITTING D.P.A. AND D.P.C.
ROT0 DIESEL INJECTION PUMPS MA
146.1/l 5
REFITTING
Prepare
- the pump (see Op. @ MA 146.0/l/
Fit
- the pump with the mounting studs in the middle of
the slots,
- the pump fixing nuts but do not tighten home.
Assemble, Fig. I:
- the injection pump driving pinion t I); hand tighten
nut (2),
- the pump drive belt with the side opposed to the
tension roller being without slack (take care not to
rotate the pump).
Unscrew, Fig. I:
- tensioner nut (3); let the tensioner load the belt
without assistance.
Retighten, Fig. I:
- tensioner nut (3) to 2 mdaN,
- pinion nut (2) to 5 mdaN.
Carry out the pump timing:
Turn the pump towards the engine to find the point
of injection, (needle facing the “0” mark on the dial).
Screw up, Fig. II, to 2.4 mdaN,
- the pump fixing screws (4); when tightening, the dial
gauge needle should not move.
Check the pump timing (refer to @ MA 146.011)
Remove the tools
Refit:
- either the plug (tighten to 2 mdaN),
- or the inspection plate.
Seal the injection pump plug.
Refit:
- the belt upper protection cover,
- the wheelarch lining,
- the accelerator return spring,
- the injector set of feed pipes.
Tighten to 2.5 mdaN.
Recouple:
- the fast idle cable,
- the accelerator cable,
- the fuel pipe,
- the return pipe, D.P.C. pump, Fig. III.
Connect to the overfuelling circuit,
- the diesel fuel return pipe (61,
- the air pipe (5).
Put the fuel filter back into place.
Reconnect:
- the electric STOP solenoid,
- the negative cable to the battery.
Prime the fuel system using the manually operated
pump located on the filter.
Adjust the injection pump controls and idling speed
as explained in Op. @ MA 146.0/l.
8531

CHECKING THE INTEGRATED ELECTRONlC
IGNITION (I.E.I.)
TEST PROCEDURE USING CONVENTIONAL EQUIPMENT
on the CX 2500 vehicle with M 25/659 type engine
l Checking the voltage in the secondary winding of each coil
0 Operating procedure: Disconnect one sparking plug and bring the end of the released wire 1 cm approx
from the crankcase. (Repeat the operation for each set of cylinders).
l Operate the starter motor:
if a spark occurs The incident is not to be attributed to the I.E.I.
Check the injection system, the valve timing, the rockers etc.
- examine the engine sparking plugs.
- inspect the circuit between the I.E.I. control unit white terminal 1 and the fuel
injection control unit terminal 15 for continuity: read 0 0, the connectors from
the control units being disconnected.
if no spark occurs The incident is due to the ignition system--ccarry on to next tests.
l Working on the primary winding of each coil
Operating procedure: Connect a 12V warning lamp of the Wedge base type between the negative and
0 the positive terminals of the coil (i.e. between terminals 1 and 3, connectors con-
netted to coil).
l Operate the starter motor:
if no regular breaks occur incident in the coil primary winding
or
incident in the E.C.U. control circuit.
if regular breaks occur incident in the secondary winding
The following checks are to be carried out with I.E.I. and fuel injection control units connectors disconnected.
l Checking the coil primary windings:
Operating procedure: Measure the resistance between terminals 1 and 9 of the I.E.I. control unit black
0 connector: Read = 2.5 0.
Warning: the ignition should be switched off.
If the reading is incorrect, investigate for a failure in this circuit.
l Checking the E.C.U. pick up sensors:
co Operating procedure: Measure the resistance between terminals 5 and 12 then 6 and 13 of the I.E.I.
control unit black connector: Read = 50 a.
l Checking the feed for the E.C.U. and earth connection, with ignition switched on
Operating procedure: Measure the voltage between terminals IO (white connector) and 2 (black con-
nector) of the I.E.I. computer: Read the battery voltage.
The same check should be carried out between terminals 2 (earth) and 11 of the black connector:
ignition switched on, starter motor operated, read the voltage.
69 l Check that the distance between the datum sensor and the flywheel ring is 1 mm + 0.5.
0 l Incident on the ignition circuit secondary winding: make sure that the resistance of each coil
winding is: 350014000 a.
8531

CHECKING THE I.E.I.
TEST PROCEDURE USING CONVENTIONAL EQUIPMENT
on the CX 2500 Turbo vehicle with M 25/662 type engine
0 Checking the voltage in the secondary winding of each coil
0 Operating procedure: Disconnect one sparking plug and bring the end of the released wire 1 cm approx
from the crankcase. (Repeat the operation for each set of cylinders).
0 Operate the starter motor,
if a spark occurs
if no spark occurs The incident is not to be attributed to the I.E.I.
Check the injection system, the valve timing, the rockers etc.
- examine the engine sparking plugs.
- inspect the circuit between the I.E.I. control unit white terminal 1 and the fuel
injection control unit terminal 15 for continuity: read 0 Q, the connectors from
the control units being disconnected.
The incident is due to the ignition system-carry on to next tests.
l Working on the primary winding of each coil
Operating procedure: Connect a 12V warning lamp of the Wedge base type between the negative and
the positive terminals of the coil (i.e. between terminals 1 and 3, connectors con-
netted to coil).
l Operate the starter motor,
if no regular breaks occur incident in the coil primary winding
or
incident in the E.C.U. control circuit.
if regular breaks occur incident in the secondary winding
The following checks are to be carried out with I.E.I. and fuel injection control units connectors disconnected.
0 Checking the coil primary windings:
Operating procedure: Measure the resistance between terminals 1 and 9 of the I.E.I. control unit black
0 connector: Read = 2.5 Q.
Warning: the ignition should be switched off.
If the reading is incorrect, investigate for a failure in this circuit.
l Checking the E.C.U. pick up sensors:
OI Operating procedure: Measure the resistance between terminals 5 and 12 then 6 and 13 of the I.E.I.
4
control unit black connector: Read 2: 5OQ
0 Checking the feed for the E.C.U. and earth connection, with ignition switched on.
d 5 Operating procedure: Measure the voltage between terminals 10 (white connector) and 2 (black con-
nectar) of the I.E.I. computer: Read the battery voltage.
The same check should be carried out between terminals 2 (earth) and 11 of the black connector:
ignition switched on, starter motor operated, read the voltage.
@ 0 Check that the distance between the datum sensor and the flywheel ring is 1 mm + 0.5.
0 * Incident on the ignition circuit secondary winding: make sure that the resistance of each coil
winding is: 350014OOOQ.

CHECKING THE IGNITION SYSTEM
USING CHECKING EQUIPMENT OUT 106 029T
The instrument can be utilised on CX 2400 I.E. with naturally aspirated engine and CX 2500 I.E. TURBO. Howe-
ver, on CX 2400 I.E. having an integrated electronic ignition system with a single connector E.C.U., it is neces-
sary to proceed as follows:
- connect the I.E.I. control unit to the black connector of OUT 105 029.T
- set the switch of the apparatus to the “1 connector” position
- I.E.I. with 1 or 2 sensors can be checked with this device.
a) Testing the ignition coil primary winding:
- The warning lamps, one at each coil, blink rythmically with the impulses transmitted to their primary win-
ding. Steady blinks indicate that there is enough current to generate a spark in the secondary winding.
- The switch situated under the warning lamps makes it possible for the primary windings of both coils to
be insulated, by pushing, in the “out of circuit“ position, any interference coming from the HT circuit when
the frequency of illumination for sensor warning lamps is checked.
- If the warning lamps blinking is correct, the failure may be caused by:
- the ignition information to the fuel injection control unit, (paragraph c),
- the secondary winding (coil wires, coils),
- any other item required for a correct operation of the engine such as injection, valve gear, rockers etc.) -
If the warning lamps blinking is not correct, examine the control unit warning lamps, (paragraph b),
b) Testing the sensors: -
The warning lamp connected with the “datum” sensor blinks rythmically with the impulses transmitted by
the peg, i.e. one blink per engine revolution, (2 sensors fitted).
- The warning lamp connected with the “flywheel pick up” sensor, blinks rythmically with the impulses sent ’
by the flywheel teeth.
The frequency of the flashes is such as they can hardly be seen.
Apparently, the lamp stays on, (1 or 2 sensors fitted).
On the CX 2400 I.E. and 2500 I.E. with normally aspirated engine, the vacuum pressure warning lamp lights
up momentarily after a sharp acceleration: this warning lamp is no longer usable on the CX 2500 I.E. with
turbocharger.
c) Tests related with the I.E.I. control unit:
E.C.U. functions: -
The rev. counter warning lamp blinks rythmically with the impulses transmitted to the rev. counter.
- The injection warning lamp blinks rythmically with the impulses sent to the fuel injection control unit
+k 8531

CHECKING THE IGNlTlON ADVANCE
of the I.E.I. system
On CX vehicles fitted with I.E.I.
These vehicles having fixed sensors, are not equipped with TDC sensors
I) Marking the TDC:
Draw a mark on the crankcase, in the opening located next to the flywheel pick up sensor
- Remove the 1st or 4th cylinder sparking plug
- Finding the T.D.C. with a locating peg: jack up the vehicle on one side and engage a gear.
Rotate the road wheel in one direction.
Mark down the place where locating pin will enter the flywheel.
Draw a temporary line on the flywheel ring. Rotate the lifted road wheel in the opposite direction, with
the pin still engaged. Mark the position of the pin in the flywheel ring. Take an average of these two marks-
which corresponds to the TDC. Draw a white paint mark on the flywheel ring, opposite the one on the
crankcase.
- Refit the sparking plug.
2) Testing the development of the speedometer advance curve:
- Connect a phase shifting strobe lamp
- Set the strobe lamp to the 2 cyl. u stroke or 1 cyl. 2 stroke position.
- Disconnect the pipe of the load correction depression operated capsule from the inlet manifold. Blank
off the orifice.
- Run the engine and check the advance curve development.
3) Testing the operation of the air-operated capsule on normally aspirated engines:
- Blank off the vacuum capsule venting orifice.
- Connect a vacuum pump to the capsule pipe.
- Run the engine to 2.000 rpm; record the advance reading.
- Create a 400 mbar depression in the vacuum capsule.
The ignition advance increases by about 15’ and the engine accelerates to 200 rpm approx.
On turbocharged engines:
- Connect a vacuum-pressure pump to the capsule pipe.
- Rotate the engine to 200 rpm. Read the advance.
- Build up a 500 mbar depression in the capsule:
- There will be a 22” increase of the ignition advance, approx. and about a 500 rpm engine acceleration.
- Build up a 500 mbar pressure in the capsule:
- There will be a -1 1 o decrease of the ignition advance, approx. and about a 500 rpm engine slowing down
- Pinking: occurs when the engine speed exceeds 1.000 rpm. The warning lamp should light up in the
following cases:
- anti-knock sensor system broken or short-circuited,
- knock sensor broken or short circuited,
- improper earthing provided by the knock sensor.
- Check the operation with the strobe lamp, and a 2.000 rpm engine speed Record the ignition timing.
- Disconnect the knock sensor:
The ignition advance decreases by IO’ approx.

2 IVIA
422.1/l OVING AND REFITTING A REAR AXLE ARM
REMOVAL
Raise the rear of the vehicle and support it on stands,
wheels free.
Remove the road wheel.
Release the pressure in the hydraulic systems.
Remove protection plate (I 1, Fig. I.
Vehicle having the A.B.S. fitted, Fig. II :
Withdraw sensor (3) and push aside the metal panel
and sensor, liberating the electrical harness from the
retaining clips.
Remove suspension cylinder (5), Fig. Ill.
(As explained in @ MA 433. l/2/.
Take off fixing lug (41, Fig. Ill.
Uncouple:
- brake hose (21, Fig. I,
- the anti-roll bar, Fig. Ill. In order to do so, extract
screws (6) and (7) and keep adjustment shims and
washers c(a)) and ccbal.
Take off nut (8) 24 mm A/F, Fig. IV.
Free the shaft and remove the arm. REFITTING
Position the axle arm (the thinner thrust cup (9) :
9.34 mm thick at CCCH facing the interior of the
vehicle, -+ l/87), Fig. V).
l/87 -+ the thrust cups are identical and the adjust-
ment is effected by means of shims facing the exte-
rior of the vehicle.
Return the shaft to its original location.
Place nut (8), new NYSLTOP nul, Fig. IV.
Tighten to 13 mdaN.
Recouple the anti-roll bar, Fig. Ill. Add the screws (6)
and (7) together with the adjustment shims and
washers found at c(a)) and c(b)) on dismantling.
Tighten screws (7) to 6 mdaN and (6) to 10 mdaN.
Reconnect brake hose (2) Fig. I, fitted with a NEW
sleeve seal. Tighten it.
Refit fixing lug (41, Fig. Ill.
Locate suspension cylinder (51, Fig. IV.
(See @ MA 433. l/2/.
ABS vehicle, Fig. II :
Refit sensor (31, (grease the outside of the sensor with
MOBIL TEMP No. I).
Tighten the screw to 1 mdaN.
Reassemble:
- protection plate (I 1, Fig. I,
- the road wheel.
Lower the vehicle to the ground.

FRONT MA
412.1/l 1
RECOMMENDED TOOLS
6303-T.
Upper arm shaft extractor. 6320-T.
Anti-roll bar link rod extractor 6602-T.
Set of three stands.
REMOVING AND REFITTING
AN UPPER WHEEL ARM
8531-8532