Xsara II 2.0 HDI 90 limp mode

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GiveMeABreak
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Re: Xsara II 2.0 HDI 90 limp mode

Post by GiveMeABreak »

dave_xsara wrote:
12 Sep 2021, 22:04
Can one of the mods confirm the OEM number for my fuel pump please?
That's correct or there is a cheaper Citroen alternative: 1671039480.

Part 1525T4 costs: £320.94
Part 1671039480 costs: £279.16

All VAT inclusive direct from Citroen - although you can source an aftermarket one now with these part numbers if preferred.
dave_xsara
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Re: Xsara II 2.0 HDI 90 limp mode

Post by dave_xsara »

Thanks Marc,
Looking through my posts you previously pointed me towards a VDO one on ebay, so I've got it coming later this week for £59.99.
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Re: Xsara II 2.0 HDI 90 limp mode

Post by dave_xsara »

New pump in and behaviour is different!

Engine cut out twice on me. When I tried to restart I could not hear the actuators or pumps. Cranking over engine don nothing. Waited a few minutes, retried ignition and actuators/pumps came back to life and it restarted.
Car is now consistently running for ~5sec after ignition switched off. This is logging P1138 - 'Permanent fault, Fuel pressure regulator . stop requested but regulator still active'. Fuel pressure 275bar.
Second logging of this fault returned a fuel pressure reading of 322bar.

Other faults logged are:

P1112 - 'Temporary fault, Fuel high pressure monitoring . Fuel high pressure regulator blocked.' Engine speed = 1895rpm. Fuel pressure = 565bar. Fuel pressure regulator open cycle ratio 0.8%.

P0571 - 'Remote fault, Temporary fault, Brake switch signal . Communications fault'

New BSI fault which I hadn't seen before - 'Permanent fault + ignition one (+IGN)'


The 5sec past ignition off is soldering the yellow connection at the sump.
What could be causing the cut outs?

We changed the high pressure regulator, but was there a filter to be cleaned?
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Re: Xsara II 2.0 HDI 90 limp mode

Post by dave_xsara »

Screenshots...
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Last edited by dave_xsara on 15 Sep 2021, 22:33, edited 1 time in total.
dave_xsara
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Re: Xsara II 2.0 HDI 90 limp mode

Post by dave_xsara »

IMG_20210915_213707.jpg
Here is the plug which I've been told to solder. There was work done here in past when something went wrong.

Edit: the work was done by dealer for this issue: viewtopic.php?t=59052
wheeler
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Re: Xsara II 2.0 HDI 90 limp mode

Post by wheeler »

I suppose it could be causing cutting out so certainly worth doing as it has the other fault code too. I would maybe re do that previous splice too incase it’s causing any issues, strange that this fault code is only appearing now.
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Re: Xsara II 2.0 HDI 90 limp mode

Post by dave_xsara »

I've checked continuity of the female plug back up to the ECU and all is okay. I probably should have been checking for resistance changes due to corrosion.
So, is it best to solder these up or would bullet/spade connectors suffice?
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Re: Xsara II 2.0 HDI 90 limp mode

Post by dave_xsara »

wheeler wrote:
16 Sep 2021, 12:36
I suppose it could be causing cutting out so certainly worth doing as it has the other fault code too. I would maybe re do that previous splice too incase it’s causing any issues, strange that this fault code is only appearing now.
That previous splice was a new wire from that joint up to the connector block at the ECU. Getting continuity between from behind the female plug to the connector into the ECU.
Will chopping out the yellow plug definitely resolve the 5s overrun?
wheeler
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Re: Xsara II 2.0 HDI 90 limp mode

Post by wheeler »

Well i cant say 100% but i have done this repair multiple times for this exact fault. The ECU is seeing some dodgy reading from the fuel pressure sensor, in theory it could be a faulty fuel pressure sensor or its connection but before i shelled out for a fuel pressure sensor id be doing the repair that will only cost a few pence & take up 15 minute of my time.
bullet/spade connectors are not a good idea for use outside as corrosion wont take long to set in. Either solder & heatshrink or raychem crimps (like the one that has been used in the last pic) after they have been crimped you heat them & they melt & seal.
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Re: Xsara II 2.0 HDI 90 limp mode

Post by dave_xsara »

I'll be doing that tonight and will report back.
In relation to the P1112 fault for blocked high pressure regulator - is there a filter anywhere to clean? I don't remember the one I swapped in during 2019 to have the filter on the end of it.
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Re: Xsara II 2.0 HDI 90 limp mode

Post by dave_xsara »

Just after soldering then up and no difference. The engine still runs on for 5sec after the ignition has been turned off.

Is this likely the sensor on the rail now or could it be elsewhere. Mot is coming up so I'm beginning to panic a bit!
IMG_20210916_225410.jpg
IMG_20210916_225441.jpg
dave_xsara
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Re: Xsara II 2.0 HDI 90 limp mode

Post by dave_xsara »

Been thinking/reading about this and I think the HP pump/regulator is the issue.

What I'm wondering (and I'd appreciate some feedback on this) is based on the below - the regulator filter is blocked with causes overrun as described below. Could the engine quitting whilst driving be due to this as well - as borne out by the P1112 fault code indicating that the HP regulator is blocked?

http://www.bba-reman.com/forums/Topic29442.aspx
the reason the engine runs on is indeed the pressure reg.bosch c/rail cp1 pumps pump at max pressure and the reg controls this down to required presure.when ign switched off p/reg power is cut,thus pressure should drop imeadatley.the injectors keep firing till presure drops below 110bar.if u remove the p/reg u will find the filter on the end of reg is choked causing presure to decay slowley and engine to run on:

How would the HP regulator filter get blocked? Is it blocked from fuel coming from within the HP pump - meaning that it might be failing? Can the regulator be cleaned - my understanding is that it is a replaceable item?

In this thread I mentioned a vibration directly in front of the driver. A few things have since been replaced/repaired and no trace of the vibration source can been found. It goes away for a while and then comes back. However, it has been present recently again. I'm wondering if it is slowly disintegrating and swarf is blocking the HP regulator?
viewtopic.php?t=59804&hilit=vibration
dave_xsara
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Re: Xsara II 2.0 HDI 90 limp mode

Post by dave_xsara »

So, its working again!
Not sure how or why, but I did notice that the fuel pressure reading at idle is now 298bar - which is within range. Previously in the post above dated Wed Sep 15, 2021 9:30 pm, the fuel pressure reading at idle was 353bar.

I'm not sure what has caused the fault to correct itself - as it was not working immediately after soldering the connections.

1. Did the EEC need time to relearn the signals from the rail pressure sensor after soldering the connection?
2. Did revving the engine to check the fuel pressure across the rev range cause something blocking the hp regulator to dislodge sufficiently for correct behaviour to occur?

So, the question now is whether I've got the problem resolved fully or just the overrun issue. I suspect that the overrun and the cutting out during driving are interrelated, but not sure if both are now resolved!


Edit: should say a massive thanks to wheeler for the advice on clipping the connection. Fingers crossed it has sorted the other issue too, but we'll see!

IMG_20210917_121534.jpg
dave_xsara
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Re: Xsara II 2.0 HDI 90 limp mode

Post by dave_xsara »

Replaced fuel filter tonight and there were traces of dirt in the bowl.
Car overran 3 times since, but is mostly behaving.

However, took it out for a drive and at the exact same places in the road, the car shutdown - so that is still not solved. Right hand 90deg corner when I go around it the car just drops to ~1000rpm and then eventually dies out. Ignition system remains on - lights on dash. However, I cannot hear the actuator and in-tank pump whirring - so something has cut them out.
After a period of a few minutes and cycling the ignition numerous times, the pumps and actuators kick back into life again and off we go again.

Would the HP regulator blocking cause the fuel system circuit to shutdown for a period of time - i.e. mechanical fault causing electrical shutdown. Or is it more likely to be an electrical fault causing shutdown?

The BSI faults are most likely phantom faults - based on wheeler's reply on page 1 of this thread. So that points solely at the HP regulator being blocked as the culprit?
wheeler wrote:
05 Jun 2020, 13:22
Ignore the evaporator temp sensor, speed info fault & the brake signal fault. They are known 'phantom' faults & will be in nearly every RHY/RHZ engine you scan.
Although before ignoring the brake switch fault just confirm the brake lights are working correctly.

If you had a charging issue I reckon there would almost certainly have been other electrical symptoms, I'd say the fault you experienced would almost certainly be caused by P0190. First off how old is the fuel filter? is this a Bosch or Siemens system?

EDIT: Just checked & it turns out the alternator fault code is also a phantom fault.
Image

Any ideas as to where I go from here?

Edit - should say that P1138 occurred before leaving for the drive.

Inside of fuel filter housing - you can see metal filings at the bottom and effect of cleaning it :
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Faults:
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dave_xsara
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Re: Xsara II 2.0 HDI 90 limp mode

Post by dave_xsara »

Started stripping down today and the filter on the high pressure regulator has a lot of filings on it.
Can I clean these off?
Would this indicate the failure of the lift pump in the tank which I have now replaced or would it point to the hp pump to which the regulator is attached?

Is there a way to check the HP pump itself?
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Last edited by dave_xsara on 18 Sep 2021, 15:20, edited 1 time in total.