P1210 fuel pressure regulator fault

[darbuck]

Thanks a million Marc, I hope I didn't come across as giving out. I genuinely thought it wasn't Available. It will give me a better idea of where everything goes.

[GiveMeABreak]

No worries. For reference, they call the above the 'Wiring Diagram' and the previous one I put up the 'Principle' diagram. It's often easier for novices to look at the clearer one when looking for a specific connection and how it all connects - but for others like yourself this one above is more practical for tracking down the complete wiring connections.

[darbuck]

Thanks Marc I get you now.

[GiveMeABreak]

One other thing Darren - just be aware that where it states ND on the diagram, this means that the colour for the wire is non descript - or any colour, so always use the pin numbers at either end to determine the correct wire and never the colour.

[darbuck]

The regulator I said I had bought arrived today and my laptop didn't charge last night so I threw the new regulator into it. Unfortunately it wasn't it causing the problem or at least not completely it does run a bit longer and actually revs a bit with the pedal. I think it was on the way out. So it's a fault either in the wiring or the ECU. Thanks for that Marc, Citroen love to make life hard for us.

[Rhothgar]

One other thing Darren - just be aware that where it states ND on the diagram, this means that the colour for the wire is non descript - or any colour, so always use the pin numbers at either end to determine the correct wire and never the colour.

You learn something every day.

Wondered what it was. ND doesn’t appear to exist in the factory manuals for the old stuff.

Seems like it’s deliberate to make life a little more challenging.

[darbuck]

It definitely seems that way. I now know at least it's not the regulator itself per day although due to the difference in running I think it was faulty so I just have to find the open in the circuit, I hope it's just the wiring is damaged.

[Rhothgar]

Stupid question but I’m good at those.

Have you cleared the error codes as per Kenny’s input?

I ask because you need to be sure that fault has been cleared.

And do you have a Lexia? I may have missed this somewhere.

Need to go back to basics if you haven’t already.

What are the four basic things a diesel needs to run?

[darbuck]

Hi Roger yes I cleared codes and yes I have a lexia aswell. I can confirm it's this code that keeps coming back and one for the exhaust temperature sensor and the glow plug relay fault. The regulator fault is referring to an open circuit. It's the only code of the three I believe could cause this problem. It does start but runs for about ninety seconds and then shuts off. I can't get to it again untill this evening but if you let me know what you think you might need let me know. your help is greatly appreciated.

[Rhothgar]

I'm afraid I'm not really much help.

Take some videos of Lexia data with Key On Engine Off and then whilst cranking so Main Parameters 1 I think.

Does it start clean and without any hesitancy?

Let's look at the fuel rail pressure live and see what happens at 90 seconds?

The glow plug relay fault sounds like something to investigate. It sounds as though the glow plugs are clearly working (assuming it starts on the button). But then the engine is unable to continue once the glow plugs go out.

There are criteria for the glow plugs staying on. Not sure what they are on your model but 90 seconds sounds quite a short time. Maybe it's not.

Maybe there is a link here. Do you mean exhaust temperature sensor? You really need the Citroen troubleshooting information to work through it. I've misplaced mine for my car but whilst it would be very similar it would not be 100% the same I doubt.

Didn't you damage the wiring to that taking the engine out? If so, you need to repair that to get that fault cleared and resolve any effect that may have on the running of the vehicle. I don't for one minute think it could stop the engine running but better to get it done and rule it out.

Have you checked fuel supply and return pipes for damage when you removed and reinstalled the engine? Perhaps it is priming up OK and then sucking air in somewhere and the regulator is having to over compensate and as that over compensates the air mass meter is being told that the fuel rail pressure is too high? There's plenty that could be wrong...

[Rhothgar]

As Marc posted this, it contains some interesting information especially the "Conditions for Fault to clear" and the "Downgrade Modes". This is all outside of my territory I'm afraid.

Are you still suffering ANY of the symptoms listed apart for the engine cutting out?

I would imagine if the fault has been cleared then it hasn't reappeared but does the engine need to run for 5 minutes after start-up to convince the ECU that the fault really has been cleared?

Also, have you done a leakback test on the injectors?

P1210 Fault Code

Fault Code:	P1210
Description of Fault:	Fuel flow regulation electrovalve: Open circuit. Open circuit on the fuel flow regulator control for 500 ms
Conditions for Fault to clear:	Driving for 5 minutes
Downgrade Modes whilst Fault is active:	Deactivation of processing of the accelerometry Deactivation of the speed limiter Deactivation speed limiter until the next time the ignition is switched on Deactivation of the cruise control Deactivation cruise control until the next time the ignition is switched on Request for Delayed Engine Stop Deactivation of the pilot and post-injection injections Deactivation of the detection of loop difference on the fuel flow rate regulator Deactivation of this compensation strategy of the injectors postinjection to postinjection Deactivation of injection compensations The ECU limits the fuel flow Deactivation of the rail pressure faults
Symptoms:	Engine hesitating, cutting out Noise Starting problem Smoke from the exhaust Lack of power
Suspect Areas:	Electrical harness Connections High pressure pump Engine ECU

[darbuck]

I'm going out shortly to it and will plug it in and doas you suggest. It's slow to start, I don't think the glow plugs they are new Bosch plugs so I know they are good I don't think they are as important on this engine I think it's more reliant on compression but as you say I will rule it out maybe a new relay I will test it. It is a ghost fault that was there before the engine rebuild.I have repaired the loom for the exhaust temperature sensor and have a new one to install as I think I damaged the other one beyond repair. I tried repairing it but it has a short to ground so cable is probably pulled internally. I have checked fuel pipes primes well gets good and firm but I can't honestly rule it out without further testing I have put down the parts canon you will be glad to hear. I cleared the fault but it comes back straight away it says open circuit fuel metering valve or something to that effect. Engine doesn't run for long and when it does there is considerable knock. I think I need to open the loom and trace the cabling back to the ECU. It's on the same side of the engine bay at least, very small mercy's.

[Rhothgar]

OK. Well you should make sure that the battery is fully charged also. Something you will not be able to do in the short time you have.

Is the battery good enough to support the glow plugs being on for 90 seconds? Is the alternator actually charging?

Lots to think about going back to basics WITHOUT spending any money.

It would be pointless replacing every component that is relied upon for starting only to find it is the wiring.

CHEAPEST THING FIRST!

[Rhothgar]

As my mate says, “If you replace a part and it doesn’t fix it then check the things you should have checked before you replaced it!”

[darbuck]

Ok so replaced the exhaust temperature sensor didn't clear code but could be to do with not running long enough. I will scope it later, it's not a priority at the moment
.

My poor attempt at a video but you can see fuel pressure is too high and I have significant engine knock, surprisingly it is showing regulator activating.