1982 Citroen CX air filter

Downloaded from www.Manualslib.com manuals search engine OPERATION No MA.IE. 144-00 : Chu~acte~istics of the (( L-Jetronic n electronic
fuel injectiari system Op. MA.IE. 144-00 5
-AIR INLET SYSTEM’
Air drawn in via air filter ( 1 ) passes through the air-flow sensor (2’), via butterfly ( 3) and arrives in the inlet
distribution chamber, each pipe of which (4) leads to a cylinder.
-
‘I
Each cylinder has an electro-magnetic injector which is located very close to the inlet valve in order to improve
engine performance.
The supplementary air control (6) is located in parallel with the butterfly, and supplies the supplementary air
required by the engine to run smoothly when cold.
_ Once the engine has reached its normal running temperature, the idling speed air-flow is provided by a by-pass
valve
$ ( 5) which by-passes the butterfly as well.
.
2
co
T
$ It is important that the system be air-tight downstream from the air-flow sensor, so that no (( secondary )) air can
I
2 be drawn in, which would falsify the air-volume reading.

Downloaded from www.Manualslib.com manuals search engine OPEdATlON N- MA.IE. 144-00 : C1 3aractcJristics o/ the e L-Jetro~ic n elcctrorlir Op. MA.IE. 144-00 9
fuel injectian systwn. E.C.U; ( ELECTRONIC CONTROL UNIT )
Apart from three integrated circuits ( I.C. ) forming the main part of the E.C.U., there are in addition only a few
semi-conducting components condensers, calibrating resistors and filters so as to avoid.any interference.
I
The function of the E.C.U. is ,to supply an impulse to the injectors, and to control their opening for a precisely
defined amount of time. The E.C.U. to this effect uses the information provided by all the engine sensors which
translate the operating conditions of the engine into electric impulses.
All the injectors are connected in parallel, and inject fuel simultaneously twice for each rotation of the camshaft
( therefore,twice for each engine cycle ), injecting half the quantity of fuel required each time With this system
it is not necessary for the camshaft angle to coincide with the beginning of injection point, which eliminates the
need for a generating switch incorporated in the distributor.
The injection impulse control is ensured by the distributor impulses. The distributor produces four impulses for
every operational cycle. Since injection only occurs twice in every cycle, the E.C.U. must divide the frequency
by 2.
The impulses coming from the distriLti, are transformated into square waves by the waveform shaper. Since
injection only occurs twice for each camshaft rotation, whereas the distributor provides 4 impulses in the same
amount of time, the frequency of the impulses must be divided by 2 in the frequency divider.
These signals are used to charge a condenser. The condenser discharge determines the beginning of injection
point; the position of the air-flow sensor flap ( which determines the quantity of air drawn in ) being the main
parameter for calculating the duration of injection.
At the multiplying stage of the E.C.U., various correction values ( full load and idling speed via throttle butterfly
spindle switch, engine temperature via the water temperature sensor, air temperature via the air-temperature sensor
located in the air-flow sensor ) are combined with the signals from the air-flow sensor and the injt,ztion frequency
in order to determine the injection duration which is transmitted to the injectors by way of impulses.
The time it takes for the injector needle to open and close depends on the battery voltage.
As the supply voltage increases, the injection duration increases.
The fact that the quantity of fuel injected depends
on the voltage is cancelled out by the fact that the injection duration is inversely proportional to the voltaqq,in the
E.C.U.
The final impulse determines the time during which the injectors are connected to earth ( injection duration ‘supplied
by the output stage ).

Downloaded from www.Manualslib.com manuals search engine ELECTRIC PETROL PUMP
The petrol pump is of the multi roller-vane type, driven by an electric motor which is energized as long as the
ignition is switched on. The rotor, which is fitted eccentrically in the pump housing, has metal roller vanes in
grooves around t.he periphery which, when they are forced outwards under the action of the centrifugal force, ensure
the system-is sealed.
Fuel is drawn into the cavities which,appear in between the roller-vanes, and is then forced into the injection
piping.
The electric motor is submerged’ in fuel. However, there .is no fire risk, since there is never any combustible
mixture in the pump housing. The pump supplies more fuel than the engine consumes under full load, so that
there is always sufficient pressure in the fuel system, whatever the engine speed. Excess fuel flows back to
the tank.
Once the ignition is on, the pump operates at the same time as the starter motor. Once the engine is running, the
airflow sensor energizes the pump.
Thanks to this type of.system, if an injector is faulty ( leaks ) the cylinder in question cannot be flooded if one
has ommitted to switch the ignition off. PETROL FILTER (1) :
A fuel filter, fitted between the pump and the injectors, prevents any impurities from reaching the injectors. PETROL PRESSURE REGULATOR ( 2 ) :
The fuel pressure is maintained constant by the pressure regulator. It comprises a metal housing
is a diaphragm., One side of the dipphragm.is subjected to the fuel under pressure, and the other 2
to the action of a calibrated spring. inside which
side is subjected
When the fuel pressure is in excess of 2 bars ( 29 psi ), the diaphragm lifts and allows fuel to flow back to the
tank.
The pressure provided by the regulator is pre-adjusted at the factory. The chamber on the side of the spring is
connected via a flexible pipe to the inlet manifold. Therefore, the difference between the pressure in the inlet
manifold and that of the fuel is maintained constant.
For any engine load, the drop in pressure at the injectors is therefore the same.

Downloaded from www.Manualslib.com manuals search engine 28 OPERATION N” MA.IE. 144-O : Ch <,c ,ng n,,d nlfjusfiup Ihe u I.-~<~tro,,ir i) <~lrr/mr,ir k’
/,,,.I i,,jrr/io,, S~S,W1, ANNEXE : D - ADJUSTING THE IDLING SPEED AND THE EXHAUST EMISSION
CHECKING CONDITIONS
1.
Checking the idling speed must be carried out
on a clean engine on which the ignition and the
valve clearances are properly adjusted and
fitted with a clean air-filter.
2. Check that the throttle butterfly returns correctly
to its stop.
3. Do not load the alternator by switching an any
of the electrical components, except the iqnition
and the electric cooling fan (s) 4.
Run the engine to bring the oil temperature up
to 70 +o 80’ C ( wait for the electric cooling
fan is) to cut in ). IMPORTANT : Use exclusively (I high tension
tachometer ( do not damage the H.T. lead of
the ignition wiring harness ).
ADJUSTMENT
1. Check that the butterfly is not jammed in position
when it is resting against its stop.
2. Wait for the electric cooling fan (s) to cut in.
3. Use screw ( 1 ) to adjust the idling speed to 850
to 900 rpm.
4. Check the exhaust emission :
The resulting amount of CO - CO2 ( corrected CO
reading 1 must be beI& 4.5 %.
In case this reading cannot be obtained, check the
valve clearances, the ignition, the fuel pressure,
the air-tightness of the aircircuit, and the complete
fuel injection system.
5. On (I vehicle fitted with optional oirtonditioning
switch the compressor on, and adjust the idling
speed from 1000 to 1050
rpm, by adjusting the
screw on the auxiliary box located next to the
electro-vol”e.

Downloaded from www.Manualslib.com manuals search engine - Calibration of thermal switch for temperature warning lamp .__._... 135 ? 3” C
- Type of oil . . .._..__.._._..___._._._._._.................,,.........._..._..._................. TOTAL (( FLUIDE 1) T
- Total capacity f
iur//rdiir/g ~~arhos ) .._._.._.......................... 5.5 litres ( 9.7,pts )
- Interchanqeable suction filter
- Filling the converter during fitting. actuate the electro-valve a dozen times.
Tightening torques :
- Electra-valve fixing screw ............................................................ 2.8 daNm ( 20 l/2 ft.Ib )
- Union-screw for oil pipe ............................................................... 3 to 3.5 daNm ( 21 l/ 2 to 25 l/ 2 ft.Ib )
- Suction filter .................................................... ........... ............. 3.5 to 4 daNm ( 25 l/2 to 29 ft.Ib )
- Contact fixing screws ................................................................... 0.2 to 0.3 daNm ( 1 11 2 to 2 ft.lb )
IMPORTANT : In the course of repairs, it is permissible to replace a 697-type ( .CX 2200 ) converter by a 693-type
( CX 2400 ) one.
However, the reverse operation ( replacing a 693-type by a 697-type converter ) is prohibited.

Downloaded from www.Manualslib.com manuals search engine OPERATION No MA. 390-O : ChrckinR thr bydraalir co’mponcnts on the u&i& f Manual stcprine r~ebidos t Op. MA. 390.0 1
CHECKING’THE HYDRAULIC COMPONENTS
NECESSARY EQUIPMENT
- 1 pressure gauge A,
0 - 250 bars ( 0 to 3650 psi )
_ 1 3-way union B (No 5 416 494 K 1
- 1 pipeC (DX 394-185 ) ..
- 1 plug D ( 2 female ends 4 1.25 and 6 9 X1.25) = =
- 3 plugs E (mole ends : r$ 8 X 1.25 ) =
- 1 plug F (
mole 4 = 9 x 1.25 1
NOTE
: Plugs D, E md F are part 01 fhe kit
sold snder number 3657-T.
PREPARATION 1.
First ensure :
- that hydraulic reservoir filter is clean.
- that hydraulic fluid is ot normal running tempe-
rature ( Carry 0~1 a road lent first i/ vt4icie
is
mid ). 8 2. Draining the circuits :
Place manual height control lever in ion, posirios,
Slacken pressure regulator bleed screw ( 1 ). 3. Fitting pressure gouge A :
Disconnect the tube (2) HP outlet from pressure
regulator.
Connect the following assembly into the circuit :
pressure gaoge A, 3way union B and pipe C
between pipe ( 2) and the pressure regulator.
This ass~nzhly mrtst remain in positioa /brougbo~~l
the test. IMPORTANT :
The testing kquance described below must be
followed.
If after the test, a component appears defective,
either replace it or repair it before proceeding
to the next test.

Downloaded from www.Manualslib.com manuals search engine II. OPERATING PRINCIPLE
The refrigerating system has four main components
- the compressor ( 4)
- the condenser ( 7)
- the pressure release valve (3 i
*
the evaporator ( 1 )
The refrigerating fluid used is the F. 12
L.64.1 a
Compressor
(4) - Manufacturer ASPERA FRIGO. type HG 700 ( or SANKYO type SD 508 on EMBAUT CLIMAT )
ASPERA twin-cylinder or
SANKYO five-cylinder rotary 1 Fitted onto the gearbox by means of a mounting bracket
The compressor circulates the refrigerating fluid draws in the fluid which is in a low-pressure vapour state
compresses it ( which increases its temperature ) and expels it into the condenser.
The condenser is driven by the engine via the water pump by two trapezoidal belts ( ASPERA ) or one trapezoidal
belt ( SANKYO ).
An electro-magnetic clutch is fitted to the compressor pulley. Its operation controlled by a switch on the centre
console is intermittent due to the presence of an ambient temperature thermostat ( 2 ) which is not adjustable, and
which senses the temperature near the evaporator cooling fins.
In case of excessive pressure in the return circuit, a pressure switch (6) opens the supply circuit to the compressor
clutch.
Condenser (7 ) - Manufacturer CHAUSSON
It allows the fluid to condense and to release its latent heat to the outside air circulating around the fins. It is
secured to the front L.H. side of the engine cooling radiator At the condenser outlet, the fluid is in the high-
pressure liquid state. The fluid flows through the tank ( 5) ( which contains a dehydrating filter ) and flows
towards the pressure release valve.
A 5-blade electric fan accelerates the circulation of air around the condenser fins.
De-watering tank .( 5) - Manufacturer : SINGER
It contains a dehydrating filter element, and is fitted with a visible level indicator, which allows the amdunt .and
state of the fluid to be checked, and a high-pressure switch (6).
The de-watering tank is fitted on the front panel by means of a mounting bracket at the rear L.H. side of the
engine cooling radiator.
Pressure-release valve (3) : It is incorporated in the heater unit, and regulates the output of fluid towards the
evaporator.
Evaporator ( 1) - Manufacturer SOFICA
The air flowing through the evaporator releases its calories, ‘which will cause the low pressure fluid to be
transformed into vapour.
It is incorporated in the heater unit upstream from the heater radiator.

Downloaded from www.Manualslib.com manuals search engine .
DEVICE FOR HEATING THE INLET AIR
It consists of the following
A - A vacuum capsule situated at the air-filter intake
B A thermal sensor, situated in the duct linking the air-filter to the carburettor
C - A,device for heatinq the inlet air by means of the exhaust (by having a take-off on the exhaust manifold shield). ASSEMBLY DIAGRAM
Carburettor
Calibrated ori fi ce for
vacuum intake
COLD AIR -
A. VACUUM CAPSULE
II I
I
t I
Position of capsule, when
not under vacuum ( flap open,
closing plate closed )
I
m-t L2
L-H ii
---+- Thermal
sensor filter
Position of capsule
under vacuum
(flap closed, closing
plate
open 1