1982 Citroen CX Ignition

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 Op. MA.IE. 144-O 1 I - PRECAUTIONS TO BE TAKEN WHEN WORKII;(G ON A VEHICLE FITTED WITH THE (t L-JETRONIC n
SYSTEM.
1.
Do not run the engine if the battery leads are improperly secured
2. Do not use a quick-start charging trolley for starting the engine
3. Never disconnect the battery with the engine running
4. When charging the battery, disconnect the leads
5. Before checking the injection system, check the ignition : (advance, advance curve, proper grade of plugs 1
6. Remove the E C U before putting the vehicle through a paint-stoving oven
7. Check the conditions of the various connections
8. Never disconnect the E,C U. while the ignition is on
9. When checking compression, disconnect the positive terminal of the coil (in order to stop the injection signal). 10.
When carrying out a check requiring an ohmmeter, use exclusively a battery-powered ohmmeter. II. FAULT-FINDING.
1. THE ENGINE DOES NOT START, OR IS DIFFICULT TO START . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 2
2. THE ENGINE STARTS, THEN STOPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 3
3. UNSTABLE OR INCORRECT IDLING SPEED, EXCESSIVE FUEL CONSUMPTION ........................ P:5
-4. ENGINE MISFIRES AT .ALL SPEEDS ........................................................................................................
P. 7
5. LACK OF POWER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ................ P. 9

Downloaded from www.Manualslib.com manuals search engine Ill. CHECKING AND ADJUSTING
1
. Energizing the system ..................................................................................................................
2. ,Fuel pump feed ( on operating the starter ) .............................................................................
3. Fuel pump feed ( with engine running ) ...................................................................................
4. Supplementary air control ...........................................................................................................
5. Air-flow sensor ............................................................................................................................
6. Resistors and injectors ................................................................................................... . ........
7. Water temperature sensor ............................................................................................................ .
Dingram 7
8. Air temperature sensor ...............................................................................................................
9. Cold-start injector, and thermal switch ...................................................................................
10. Switch on throttle butterfly spindle ( idling speed function ) ............................................ 11
Switch on throttle butterfly spindle ( maximum power function ) ...................................... 12.
E.C.U: ......................................................................... ..~ ............................................................... . . Diagram 1 I ANNEXE : A
: Checking the ignition .................................................................................. Page 25 B
: Checking the air circuit ................................................................................ Page 26
C : Checking the fuel system and the fuel pressure ........................................... Page 27 D
: Adjusting the idling speed and the exhaust emission .............................. Page 28 NOTE
: On the wiring harness for the injectors, the numbers of the terminals on the E.C.U. terminal board are
visible on the rear section. after having withdrawn the casing secured by the end screw.

Downloaded from www.Manualslib.com manuals search engine 1. Energizing the system : ( DIAGRAM 1 )
_ Disconnect the E.C U
- Switch the ignition on
Using a voltmeter. ensure that each point in
dingrm 1 is effectively energised. after having tested the
earthing. If not, switch off the ignition. and test the circuit using a battery operated ohmmeter. With the
voltmeter connected between terminals ( 1 ) and ( 5) of the E. C.U., operate the starter the voltmeter must
register the ignition impulses If it does not. check the ignition
( ANNEXE A ).
2. Fuel pump feed ( on operating the starter ) ( DIAGRAM 2 )
- Disconnect the E C.U.
- Switch on the ignition
- On operating the starter. the fuel pump (
secureri rrt/rler the I c~hiclc’. uoor IIJO K. ti. ronr (, l~eol I must be
heard to operate by someone standing close by
If not switch off the ignition, and test the circuit using a battery operated ohmmeter.
The resistance between terminal (( 88 d H of the relay assembly ( c~r~tler 111~
L,H. honr/llor)~p ) and earth
must be 1 Q approx-
Make sure the petrol pump is properly earthed.

Downloaded from www.Manualslib.com manuals search engine Op. MA.IE 444-O 15
3. Fuel pump feed ( with engine running ) : ( DIAGRAM 3 )
- Disconnect the E.C.U.
- Disconnect from the air-flow sensor the air hose to the butterfly housing
- Switch on the ignition:
- Actuate the air-flow sensor flap by hand’ when the petrol pump contact closes the pump should be heard
working.
If not, test the circuit using a
battery operated ohmmeter, without forgetting to test between terminal G 36 ))
on the air-flow sensor and terminal H 20 .)) on the E.C.U. for continuity ( The 2nd terminal is not connected
to the E.C.U. ).
- The resistance between terminals (( 86 b H and G 85 )) on the relay box f //j/nor thc~ I~./I. h<~ntllnr~tp ) must be
between 52 and 78 12.
P 4. Supplementary air control ( DIAGRAM 4 )
4
c
5
6
- Disconnect the E.C.U.
-E
? - Check that the supplementary air control is properly connected ( arrow on the casing )~
In
If it is fitted the wrong way round. the port may be blocked.
- The resistance between terminals (( 34 1, and (( 48 )) on the- supplementary air control must be 50 Q approx-
- Visual checking the port on the supplementary air control must be open when the engine is cold, and closed
when the engine temperature is above 60” C
- With the engine cold. if the air pipe to the supplementary air control is flattened the engine rpm must decrease.
With the engine warm, if the air pipe is disconnected, the engine must accelerate.

Downloaded from www.Manualslib.com manuals search engine 9. Cold-start injector, and thermal switch : ( DIAGRAM 9 )
- Disconnect the E.C.U.
- Remove the cold-start injector, and place it above a graduated container.
- Disconnect the thermal switch, and connect terminal (( 46 )) to earth
- Switch the ignition on and actuate the starter motor. the quantity delivered must be approximately
135 cm3 /min ( 8 l/4 cuin’min 1.
- Disconnect the injector: its resistance must be 4.2 Q at 20” C
- Connect the injector to the thermal switch.
- If the water temperature is below 35” C, on operating the starter motor, the cold-start injector must supply
petrol for the followinq amounts of time
- 7.5 sets for a temperature of (( - 20” C ))
-5 ” ” (( - 10“ c N
-3
” cc 0: c ))
-1 ” ” (( 20” c >)
- On operating the starter. terminal (( 4 )) of the E.C.U. terminal board must be enerqized ( voltmeter between
terminals (( 4 )) and 0 5 )) 1.
10. Switch on throttle butterfly spindle ( Idling speed function ) : ( DIAGRAM 10 )
- Disconnect the E.C.U
- Using an ohmmeter, check that there is no resistance between terminals N 2 H and (( 18 H of the multiple
connector, without touching the accelerator pedal.

Downloaded from www.Manualslib.com manuals search engine OPERATION No MA.IE. 144-0 : (,hcrkir~g m/cl nrl;tts/ir/<~ I/W a I.-J~~/m,i~ ~~otectrot,ic Op. MA.IE. 144-O 25 fi~cl irijection systc~rti.
ANNEXE : A - CHECKING THE IGNITION
THE ENGINE TURNS, BUT DOES
NOT FIRE

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.