Pauls HDI Xantia Exclusive.

[RichardW]

I sort of assumed it was earthed via the ECU Paul, but maybe not...??? Figures look OK on the vid - seems to be doing what it should. Not sure it moves things along!

Edit... found this pin out the other day - looking at it again, the reg is actually fed with 12V off the double relay, and then the ECU must modulate the earth signal somehow....



On the cruise front, mine is fitted with a clutch switch, which can be seen working, but there is no secondary brake switch present - it doesn't change state when the brake is pressed.

[citroenxm]

I thought the wassit % was a bit high at 16%..

If I had a Wiring diagram, I could possible do better point to point measurments then..

[RichardW]

I'll ask Mandrake if he can dig out a wiring diag from Sedre....

If I get a chance I'll stick mine back on and make a few notes of Reg position vs engine speed.

[citroenxm]

WOW! Thats brilliant. What language is it in French?

I noticed my Brake Switch in the ECU does work, but Ive no clutch switch ..

[citroenxm]

Its itallian...

I assume the A/C pins are for Cruise control inputs, from stalk, main switch etc...

[taffy]

seams to be intermitant as ur ocr % has been different over the two different times at idle....id be doing some contunitity tests on the fpr wireing and fpr wireing moving the wires at same time perhaps as its only them which seam to dictate to the ecu whats going on...aswell as the throttle potentioner...maybe position the lexia on a table outside the car so you can see it from under the bonnet and whilst idleing move some wires and see if it shows thats what i tried anyway

[taffy]

have you physically had a look at the fpr as there are two differnt heads..one with a closed tip and one with an open tip and the later is more prone to blockages/problems

[citroenxm]

Went out with that diagram above and ALL my pin to pins and pin to earth were ALL 0.1 of an OHM! so NO high resistance anywhere.

All I can assume is theres another Dickie FPR on the pump and I need to try another one!!

[taffy]

i hope THATS it lol

[Hell Razor5543]

So long as it's a Dickie FPR, and not a DickieG! He might not appreciate it!

[citroenxm]

Heres a thought HELPERS!

The fuel Filter unit has got a LOW PRESSURE Circuit regulator in it... Would that be causing an issue??

The low pressure cuircuit has to be correct for the Engine Pump to draw from to pressure up the High Pressure. Would a pressure issue there cause a high pressure issue?

I swapped filter elements, but I never swapped filter houses???



Direction of the fuel flow (as per arrows).
(23) low pressure regulator.
(24) thermostatic sensor.
(25) filter element.
C:return to fuel tank.
D:heated fuel inlet (coolant outlet housing).
E:fuel outlet (to coolant outlet housing).
F:fuel inlet.
G:fuel outlet (to high pressure fuel pump).
The low pressure regulator controls the pressure of the fuel in the low pressure circuit.
Circuit pressure:ð 2,5 bar.

[taffy]

well i covered this paul as my old filter housing it was missing and it caused no probs so it wont hurt to remove it as a test im also thinking that fuel regulator ufo thing in the fuel line??

[taffy]

remove 23 it just unclips

[citroenxm]

I have got the CORRECT pressure figures that the low pressure curcuit should be reading etc.

How would I go about connecting a Pressure guage to it to see what its reading...

[citroenxm]

2 - Deactivator of the 3rd piston of the high pressure fuel pump (1208-6)(1208-6)
2.1 - Role.
Role of the deactivator of the 3rd piston of the high pressure fuel pump :
To reduce the power absorbed by the high pressure pump if the vehicle is used at low load.
To limit the high pressure quickly in the event of a problem.



E:using 3 pistons.
F:using 2 pistons.
(4) high pressure piston.
(5) deactivator of the 3rd piston of the high pressure fuel pump.
(7) fuel suction valve.
(8) delivery ball valve.
(9) suction valve return spring.
(12) push rod.
Components of the deactivator of the 3rd piston of the high pressure fuel pump :
An electromagnet.
A push rod which moves under the action of the magnetic field created by the electromagnet.
When the 3rd piston deactivator is not energised :
The fuel suction valve (7) is held against its seat by the spring (9).
The cylinder is closed.
The action of the pump shaft cam leads to a pressure being created.
The fuel pressure lifts the delivery valve (8).
The fuel is directed towards the high pressure outlet of the pump.
When the 3rd piston deactivator is energised :
The push rod (12) raises the suction valve (7) from its seat.
The cylinder is open:No pressure is created.
The fuel is directed towards the low pressure part of the high pressure pump.
2.3 - Electrical features.
Control:injection ECU.
Type:"all or nothing" control through earth.
When the 3rd piston deactivator is energised:the pump operates on 2 pistons.
When the 3rd piston deactivator is not energised:the pump operates on 3 pistons.












G:high pressure regulator not energised.
H:high pressure regulator energised.
A:high pressure fuel outlet (to the common injection rail).
B:return to fuel tank.
E:high pressure fuel circuit.
(13) spring.
(14) electric coil.
(15) magnetic core.
(16) ball.
The fuel high pressure is regulated by modifying the rating of the high pressure fuel regulator.
The high pressure fuel regulator consists of 2 pressure control circuits :
The electrical circuit which acts directly on the high pressure which controls the electromagnet of the high pressure fuel regulator (injection ECU).
The mechanical circuit which provides a minimum pressure and dampens pulses.
3.3 - Mechanical operation.
The high pressure fuel circuit is subject to pressure variations.
The fuel high pressure increases when a pump piston delivers.
The fuel high pressure decreases when a diesel injector is opened.
The movement of the ball dampens pressure variations.
3.4 - Electrical operation.
When the high pressure fuel regulator is not energised :
The fuel high pressure opposes the mechanical action of the spring (13).
The regulator opens for a high pressure which is greater than the spring pressure (ð 100 bar).
The fuel released by the high pressure regulator returns to tank through the outlet "b".

NOTE : Engine off for 30 seconds, there is no residual pressure in the high pressure fuel circuit.
Pressure rise control phases :
The injection ECU supplies the high pressure fuel regulator with an OCR current.
The coil of the high pressure fuel regulator drives the magnetic core (magnetic force).
The force applied to the ball is the sum of the spring force (13) and the magnetic force of the core.
The cut-out value of the high pressure regulator increases.
Pressure reduction control phases :
The injection ECU reduces the OCR supplied to the coil of the high pressure fuel regulator.
The coil of the high pressure fuel regulator drives the magnetic core (magnetic force).
The force applied to the ball reduces.
The cut-off valve of the high pressure regulator decreases.

NOTE : OCR : Open Cycle Ratio.
3.5 - Electrical features.
When the high pressure fuel regulator is not energised:the pressure is limited to ð 100 bar.
Control:injection ECU (earth).
Variable voltage control (OCR) :
Maximum voltage (maximum OCR)=Maximum pressure.
Minimum voltage (minimum OCR)=Minimum pressure.
IMPORTANT : After switching off the engine, wait for 30 seconds before starting any repair work.