Is my Xantia TD diesel pump knackered?

[andmcit]

or are the injectors duff from the car being little used?

I've got a 1.9 Xantia TD VSX estate on an R plate with all the bells and
whistles. Thing is, today after a long period of layup where issues with
the lighting electrics were fettled to work again, the car is running quite
poorly at any revs above 1800. The engine will start and run happily
enough ticking over at the correct revs. It does rev up OK too BUT as
soon as it gets to the seemingly critical 1800 revs it's as lumpy as hell
and chuggs out a whole load of blue/grey smoke and doesn't appear to
increase any higher in the revs - unlike my other diesel that will happily
run up to 5k if I'm deaf enough.

Am I looking at a new diesel pump/injectors? The problem doesn't get any
better whether the engine is allowed to warm up and now just to irritate
me further (probably from prodding things about in the engine bay)
the confounded rev counter isn't working now either...

Before I take a lump hammer to everything, anyone got any ideas?

Andrew

[lolingram]

Sounds as though the pump may have sat a while with some water inside...

I've got a 1.9 Xantia TD VSX estate on an R plate with all the bells and
whistles. Thing is, today after a long period of layup where issues with
the lighting electrics were fettled to work again, the car is running quite
poorly at any revs above 1800. The engine will start and run happily
enough ticking over at the correct revs. It does rev up OK too BUT as
soon as it gets to the seemingly critical 1800 revs it's as lumpy as hell
and chuggs out a whole load of blue/grey smoke and doesn't appear to
increase any higher in the revs - unlike my other diesel that will happily
run up to 5k if I'm deaf enough.

Am I looking at a new diesel pump/injectors? The problem doesn't get any
better whether the engine is allowed to warm up and now just to irritate
me further (probably from prodding things about in the engine bay)
the confounded rev counter isn't working now either... Evil or Very Mad

Before I take a lump hammer to everything, anyone got any ideas?

[andmcit]

I've run the engine for lengthy periods over the last few months it's
been sitting about unused. It ran very well a fortnight back and certainly
didn't smoke like it does now and I'd like to think I'd have noticed the
car's failure to rev...

Andrew

[Peter.N.]

Firstly I would try changing the fuel filter. Injector and pump problems are very rare, unless, as lolingram says, its had water in it, but if you only ran it a fortnight ago it sounds unlikely, unless you can account for it getting into the fuel. Also check that the air intake hasn't become obstructed somewhere, try running it with the pipe to the inlet manifold disconnected.

[RichardW]

"Am I looking at a new diesel pump/injectors? The problem doesn't get any
better whether the engine is allowed to warm up and now just to irritate
me further (probably from prodding things about in the engine bay)
the confounded rev counter isn't working now either... "

Is this car ECU controlled? If so then I think you have narrowed down your problem - sounds like the ECU has lost contact with the No 3 injector lift sensor and / or the crank position sensor.

[CitroJim]

Richard, I'd say exactly the same

If the ECU loses either the Lift or TDC sensor, the pump will fall back to running in a fully retarded state and these pumps have a very wide timing range under ECU control. The pump itself is fine, otherwise the engine would not run at all. The lumpiness at 1800 rpm when the engine will shake quite violently is a sure sign of timing being right out.

The timing control is done in a clever way: There is what is very similar to a petrol fuel injector on the bottom of the pump and this allows a controlled amount of diesel into a chamber behind a piston. The more pressure the injector lets through, the more this piston is pushed against a spring and the more timing is advanced. This piston has a rack connected to the HP pump assembly which rotates it relative to the pump cam lobes.

The duff sensor is best tested using an oscilloscope to observe wave forms from but do check connectors first. It is so easy to leave the Lift Sensor disconnected when working on the engine.

I'd also check the cambelt timing as it seems to me, from the symptoms, that the timing is way off. Crank to pump to cam timing is very critical on these engines despite electronic control.

[jeremy]

If the diesel pump is damaged the chances are that its injection pressure is reduced. Mechanical type pumps don't produce maximum pressure at low revs and diesel engines aren't that happy about starting anyway (hence the use of glow plugs) So if it starts readily and runs - the injection pump is probably OK.

So then its starting to misbehave when its put under stress - which immediately suggests that the fuel supply is restricted - filter? Collapsed hose, priming bulb . . . .

[CitroJim]

Andrew,

Is the Engine Management ("K") light on?

[andmcit]

Rightho.

I've only just got in so haven't had time to take-in everything posted yet
or check/act on any comments made!

Thanks everyone for your posts on this so far. I'm a tad bit concerned as the
car has had a fair bit of time spent sorting (non mechanical) issues out on it
and it could all now be to waste, which would be a real shame.

There is NO 'K' light illumination.

There is an ECU - I'll check if it's just the VSX one in daylight tomorrow.
I'd imagine being a keycode car it will, though the code has been
programmed out of the loop in the past with a previous owner. I'll clutch
at any straw so this may sound stupid, but could disturbing the keypad or
straightening the duff wiring someone's hacked about in the radio console
in the past affect the running of the engine!?

No, I didn't think so...

On a rerun through what happened the latest time I ran the engine,
the lumpiness seemed to be there BEFORE the rev counter copped out
- I recall this now as I was reading it's revs as I tried holding them to 3K+.

The engine actually starts after a few short churns after timing the
glow plugs correctly, the idle is fine and it doesn't smoke until the revs
are at the higher 1800's and it certainly maxes out at no more than
about 2k revs with mountains of smoke and the rattles and shakes of
an unhappy engine.

Otherwise, there are no rattles, bangs etc etc and the car can't be driven
the way it is which it could be a fortnight back.

If actual fact, all I can imagine that's 'changed' is the car has been parked
facing the opposite direction if any hefty weather has directed it's attentions
onto it!! Said I was clutching straws!!

OK!! Being a bit more practical for a minute, I did do a visual check of all
the obvious cut off's, wire feeds and adjustments to/on the pump, and did
recognise the old thermal adjusting/cold running cable running to the
diesel pump running off the thermostat water housing - this caused grief
in my Cx dieseling days...

Beyond new glow plugs and leak off pipes experience with the XUD has
been happily sparce until now and I'm far happier with fuel injection which
99.9% of the time sits there and just works - end of!!!

Where may I find the EGR and lift sensor - remembering I don't normally
'do' diesels!?



For once I'm all out of ideas on this one. Guess my wallet could go as a
lamb to the slaughter to a diesel specialist only the car isn't taxed/mot'd.

Andrew

[caveman_si]

You havent moved any of the airducts prior to the car becoming lumpy and smokey?

If so have a look at the turbo. I had a similar problem with my car smoking badly and being lumpy on boost. AS well as sounding like a bag of nails in a washing machine.

Turned out to be a broken turbo, it had swallowed something at the garage when they did some work on it and made a mess of the turbo.

An easy check is pop off the inlet air duct to the turbo and have a look inside to see the condition of the turbo. You get to it from underneath and wil need a cammera pop the duct off stick the camera in and take a pic.

Fingers crossed its not the turbo.

[CitroJim]

Andrew,

Time to get logical now. Some exceedingly good suggestions have been put forward and it looks as if the failed tacho may be a red herring if the K light is off. If either the TDC or Lift Sensor is duff, or the ECU fails to adjust timing, the K light will be on. The K light will illuminate at initial ignition on and extinguish as soon as the engine is running under normal circumstances.

Jeremy makes a valid point that fuel supply may be severely restricted and caveman_si the turbo and ducting which may be severely restricting airflow. Either or both will cause the symptoms you have. Mouse nest in the air filter perhaps?

A good test is to bypass the turbo completely by slipping off the duct right at the inlet manifold. If this is the problem, the engine should rev OK and the induction roar will be somethig to behold The turbo will still spin doing this test and if you can hear it over the roar, you should be able to both hear it whilstle up and feel boost pressure on the disconnected duct. Be careful though to keep your hand away from the open inlet manifold as these engines can suck very hard.

The EGR valve perhaps might be stuck open and the above test will tend to mitigate this as there will be plenty of fresh air going in through the gaping orifice in the inlet manifold to adequately dilute the exhaust gas coming in through the EGR valve.

The EGR valve is located down under the inlet manifold in square H2. You can just see it in the picture, looking like a miniture UFO.

Adequate fuel flow should be able to be determined by slipping off the fuel return line on the back of the pump where the leakoff pipes connect. A healthy flow should issue from here with the engine running and you should also be able to squirt lots out just by pumping the priming bulb.

The duff rev counter and no K light may point to the ECU having died in a big way or having lost all its power. Check the supply fuses and the big ECU connector and double injection relay next to the ECU. I doubt the ECU being totally duff as it also controls the glowplug operation. It controls post heating by leaving the glowplugs in operation on cold idle until the coolant has reached around 60 degrees. As the cold engine goes off idle, the glowplugs will extinguish and will relight on return to idle if the coolant has not reached temperature. This may help to diagnose if the ECU is doing anything useful and perhaps to determine if the glowplugs extinguishing above cold idle has any bearing on the problem.

You say it has been standing a bit. I wonder if in the time it has low compression or a valve or three are a bit sticky or tight? It might just be worth a check of valve clearances. This is a very long-shot.

The equivilent of the Waxstat on the later engines is the electrovale and cable up on the bulkhead (K1 in the picture, but invisible) with the cable running to a lever on the back of the injection pump. It only controls cold fast idle and does not do anything to the timing of the pump.

Hope that helps a little Andrew.

[goldfinche]

Hi I dont wish to throw a spanner in the works so to speak but no one has sugested checking the cam belt, is there a chance that it has skipped a tooth?? Worth a check,even if it is only to clear it as a possibility.
Best of luck.
Cheers.
Geoff.

[andmcit]

Thanks again for the further input.

I intend spending some proper time with the car tomorrow evening having
just been relieved of a big chunk of dosh after a visit to the vet's this
evening...

Andrew

[Sturdybloke]

Is that some kind of sensor in D4? (at the back of the pump) If it is what would it tie in with?

[CitroJim]

Is that some kind of sensor in D4? (at the back of the pump) If it is what would it tie in with?

That is the connector to the Needle Lift Sensor on No.3 Injector. Certainly one of the suspects...

is there a chance that it has skipped a tooth?? Worth a check,even if it is only to clear it as a possibility.
Best of luck.
Cheers.
Geoff.

Absolutely Geoff Suggested way back in the thread! A real possibility and one that should be checked soonest.

Thinking on about this again, check the coolant temperature sensors are OK. These are the green and blue ones in the thermostat housing.