C5 X7 no start (or only runs for fraction of a second)

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MattBLancs
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Re: C5 X7 no start (or only runs for fraction of a second)

Unread post by MattBLancs »

For clarity, pipe pictured above is return from high pressure pump back to fuel filter.

Air bubbles in priming bulb to fuel filter inlet quickly pumped through and no further bubbles here (tank pickup has been off again as turned out that was leaking when tank refilled. Cross threaded and I wasn't happy about it either :rofl2: )

Priming bulb quickly goes from soft to firm to very firm when pumped.

Battery back on charge, out for the afternoon will be back with Diagbox either later today or tomorrow morning.


Matt
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MattBLancs
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Re: C5 X7 no start (or only runs for fraction of a second)

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Ok, pretty picture first:
Screenshot of Torque App during a start attempt (X2, hence the two peaks)
Screenshot of Torque App during a start attempt (X2, hence the two peaks)
Above is from the Torque App on my phone - wondered if a smart phone and eBay OBD2 adapter would have a shorter refresh rate than the (old) Toughbook and Diagbox.

Helpfully the app has a stab at labelling the magnitude of the peaks. Does anyone know what I should be seeing as a minimum fuel pressure?

Diagbox, under Fuel Circuit Information, under Standard Parameter Measurement, under Injection ECU section,

States "Reference Fuel Pressure" and a figure of 0251 Bars. Does this suggest 25700 kPa ( = 257 bar) is above the minimum threshold hence ok for running?

Have the usual fraction of a second "cough" momentary running still.

Currently logging following fault codes:

Injection ignition: P1351
pre heating relay circuit

Electronically managed suspension U2005
Triggering (vehicle speed receipt anomaly)

Under inflation detection U1213
Fault in this vehicle speed information received by the can from the ABS or ESP ECU

Multifunction display: F085
Fault no communication with parking assistance ECU

(Parking aid communication error)

Radio or radio telephone (radio part)
F085 no communication with the parking assistance ECU
F905 fault on auxiliary audio input number one
F907 fault on auxiliary audio input number two
9931 inconsistency of the configuration (CD changer present coded absent)

Driver's door module
F9D1 passengers mirror mechanism sensor inputs fault




There's a lot more little faults there than when scanned previously, but I can't see why any of the above would prevent it running.

Drawing a blank really.


Tomorrow may give it another kick into life with the easy-start and then see what live data from it running reveals, if anything.

Any/all suggestions welcome!

Matt
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bobins
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Re: C5 X7 no start (or only runs for fraction of a second)

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Entirely left-field suggestion, but I have a vague memory that these have a 'strangulation' flap on the intake side to cut air supply to the engine to make sure the engine stops when you turn off the ignition* - though I'm sure I'll be corrected in a nano-second :lol: I would go out and take a photo of mine, but it's dark out there and there's creepy crawlies out there :lol:

*- and assist in emissions etc.
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MattBLancs
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Re: C5 X7 no start (or only runs for fraction of a second)

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Left field suggestions equally gratefully received!

Think you are right in terms of there being one (my understanding is it closes quickly on shut down and minimises the judder to a stop that diesels without this silly flap might do. I'm not aware of any other purpose. There can be "swirl flaps" in the intake - they do have an emissions related intent (and potential for somewhat catastrophic failure in certain BMW engines??) - but think the anti judder "throttle" is worth checking.

Think is on the inlet manifold, front and centre in engine bay. Will have a play with my borescope in the morning.

(Note for grammatical pedantry as I find it amusing: borescope rather than endoscope. The later intended for up your bottom! Hence an entirely different type of conversation follows "I'll have a play with my endoscope in the morning" :-D )

Night all, thanks for the suggestions,

Matt
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bobins
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Re: C5 X7 no start (or only runs for fraction of a second)

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MattBLancs wrote: 26 Aug 2022, 21:33
(Note for grammatical pedantry as I find it amusing: borescope rather than endoscope. The later intended for up your bottom! Hence an entirely different type of conversation follows "I'll have a play with my endoscope in the morning" :-D )

Night all, thanks for the suggestions,

Matt
You know what you can do with that thing ! :lol:
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MattBLancs
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Re: C5 X7 no start (or only runs for fraction of a second)

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Tarp, to give a chance of actually seeing the screen in bright sunshine!
Tarp, to give a chance of actually seeing the screen in bright sunshine!
Cheap borescope and the old Toughbook
Cheap borescope and the old Toughbook
Those of a nervous disposition my be relieved to hear that having had overnight to think about it, I have very firmly decided that this shall remain true to its intended purpose - a borescope - and so the images that follow are of the car's internals rather than my own! :rofl2:
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Re: C5 X7 no start (or only runs for fraction of a second)

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Anti shudder valve = open
Anti shudder valve = open
Engine and ignition off at present. Anti shudder valve open.

Beyond valve is IAT sensor
Beyond valve is IAT sensor
Here's the inlet air temperature sensor visible beyond the valve. Beyond that we approach the EGR connection and so all turns black and grimy. Not easy to get any meaningful imagery from that point onwards. Instigates a desire to remove the inlet and clean it out, but that's another day's job when I've nowt else to do.

May have a go turning engine over and seeing if that valve shuts when it is supposed to be open (seems unlikely) but will need a second pair of hands to turn the key whilst I hold the borescope and try not to drop the laptop (sat on top of the engine for the above images, but that won't work when it's jiggling trying to start) My wife is out with the boys at present, so nearer dinnertime when I will get chance for that.


Matt
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Re: C5 X7 no start (or only runs for fraction of a second)

Unread post by xantia_v6 »

If the engine runs on easystart, then the strangler must be open, and the problem is a lack of fuel.
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bobins
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Re: C5 X7 no start (or only runs for fraction of a second)

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It ran on easystart only with the intake pipe removed :-k
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MattBLancs
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Re: C5 X7 no start (or only runs for fraction of a second)

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bobins wrote: 27 Aug 2022, 11:37 It ran on easystart only with the intake pipe removed :-k

Ah, for clarity, intake pipe loosened and extended straw stuck in the gap between rubber hose and alloy spigot.

Actually, the strangler valve is after said connection.

I wondered if it was gummed up and hence slow to move.

But does make sense what said about Easy-start = fueling issue.

Matt
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Re: C5 X7 no start (or only runs for fraction of a second)

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Hmmmm, to bottom out the strangler theory, now had some help available to turn the key. So I manned the borescope whilst it was being turned over.

Valve doesn't move, stays fully open when ignition turned on and when engine turned over. Even following a "cough" valve still doesn't move (hypothesis: cough insufficient to class as "engine running" hence no need to shut the valve when letting go of the key)


I've had a go with the Easy-start and well, did not find it started easily! I've not had much experience of using the stuff but spraying it in ever increasing squirts into the intake gave me no joy. Tried with extended straw (and it didn't spray well like that, more sputtered out) and with rubber hose removed and squirts directed up the alloy spigot.

A few bubbles seen in the fuel pipework (particularly the HP pump to filter return leg I've been watching)


So going to...

... fit the new mudflaps and sit and have a think.

Matt
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MattBLancs
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Re: C5 X7 no start (or only runs for fraction of a second)

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IMG_20220827_153322433.jpg
Maybe a little overboard with the fixings, but is only into the plastic
Maybe a little overboard with the fixings, but is only into the plastic
Cheap stainless hex head self tappers, M4 stainless penny washers, cardboard template and a tendancy to over complicate things....
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Rp0thejester
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Re: C5 X7 no start (or only runs for fraction of a second)

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I hope that's the rear of the car, if its the front they gunna blow right off
Ryan

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MattBLancs
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Re: C5 X7 no start (or only runs for fraction of a second)

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Yes, rear mudflaps pictured. The old one (original fitment from new judging by the date stamp in the plastic) is quite a bit taller. That sat on just 3 fixings - two into the plastic edge of the bumper (as per the new ones, but different fixing positions - one of the redundant holes is visible above the new flap) and a third on the underside of the bumper. New ones omit this one.

Front ones are two fixings, shared position with wheel arch liner (which has the female plastic fitting that receives the screw) and also passed through the end of the plastic sill cover.
The third fixing of the old flap = into the underside of the sill cover.
New ones have a third fixing on top edge of the flap - same plane as the other two. This would require a new hole drilling into the steel wing, which I don't fancy doing really. There's only a tiny edge of the steel - if there was more to play with I'd fit a Rivnut and a set screw.

Obviously at the moment is little chance of them being blown off as don't think I can get much speed up pushing it by hand! :-D

Matt
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Rp0thejester
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Re: C5 X7 no start (or only runs for fraction of a second)

Unread post by Rp0thejester »

Lol, is she still not starting? Is it diesel bug? Or something else?
Ryan

'99 Xsara 1.6 X (Red) with Sunkissed bonnet. T59 SBX
'54 Astra Estate 1.7DTI (Artic White)
'06 C8 2.2Hdi Exclusive (Aster Grey)

Champion of Where's CitroJim :-({|=
Yes I ask the stupid questions, because normally it is that simple.