Xantia info reqd

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Xantiargh
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Xantia info reqd

Post by Xantiargh »

Hi all
1995 Xant 1.9 TD LX, owned for about 3 and a half weeks.
On cold starts it idles rough for 5-10 seconds before starting/running fine til next cold start. Glow plugs, filters, etc all changed so I am now looking at air ingress. Already changed leak-off pipes and stop but no improvement.
Question:
If I pump the primer til hard it goes soft in seconds. should it stay hard once the system is pressurised if there are no leaks?
The car is returning 33-35 mpg which seems poor. Also doesn't pull well above 60 though if pushed for long time will reach 90 eventually.
It just seems a bit gutless to me. It doesn't smoke, or at least not that I've noticed, either on starting, or hard acceleration. I've revved the engine warm and you can feel the intercooler hoses bulge and contract, plus turbo can be heard whistling in low gears so it appears to be in order.
Question:
Would air ingress affect mpg and/or performance?
A few more:
The engine sounds quite clattery to me, but then its my first diesel. I'd like to check the valve clearances and the timing.
Is this something I could do myself or is it best left to a competent mechanic?
Do I need any special tools (apart from timing m8 screw kit) to access any awkward bits?
I'm quite prepared to tackle stuff armed with the right info, but changing the glow plugs (Bosch pump... b*tch) and suspension spheres is about as techie as I've got so far.
All info apprec. [:D]
Mike
David W
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Post by David W »

Mike,
I was close to advising you hopped over here for more Citroen based info!
Did you see my final reply to you "on the other side"? Perhaps you did as you've been feeling the boost hoses.
Namely...
"Cold starting: OK you've got decent glow plugs and it is a good starter except for 5secs of chugging. This is close to OK but do check that cold fast idle device is holding the revs up at first then releasing the idle to normal. Also try not turning the key to start until 4 secs after the light has gone out rather than doing two glowplug cycles.
Hydraulics: New rear spheres will transform the ride if they were almost flat. What about the fronts?
Brakes: This on-off feel is very common. Try bleeding them first. After that there is another dodge I'm going to try soon and that is to remove the spring from the pedal rod as advised by Dave Burns here. This spring was only put there to make the brakes feel "normal" to non-Citroen folks. I understand removing it will stop the last bits of annoying pulsing. I do not advise you do this, merely mention it!
Engine Power/Turbo: Are you sure that comparisons with faster cars aren't giving a false impression of sluggishness. Someone familiar with the 1.9TD would soon tell you. Is yours an estate? Do look at the turbo hoses though.
Intake air route is...Air intake behind headlamp-air cleaner-rubber elbow hose-plastic tube-turbo-plastic tube-heavy rubber hose-intercooler-heavy rubber hose-plastic tube-short rubber joiner-inlet manifold.
Intercooler is in front of the coolant radiator.
A rough check for a working turbo is to get the engine warm and then rev it while looking at the rubber hoses to/from the intercooler, you'll see them swell a little with the boost pressure.
You can also easily tee in a pressure gauge (0-20psi range)to the small bore hose that goes to the injector pump from the inlet hose and see what boost pressure you're getting."
Let's see what the others say.
David (MM)
Xantiargh
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Post by Xantiargh »

Blimey, you are everywhere! [:D] Yes, I did see your post, and have groped the hoses. Nothing loose that I can see, though I cant see too well behind the engine.
I haven't tried the pressure gauge yet. I assume I can do that test on the driveway(?).
An update, all spheres bar anti-sink have been replaced, the brakes are much better, but I'm going to run hydraflush though as the LHM is orange. I don't my car has been shown much love.[:(]
The coldstart cable is permanently slack. I need to adjust it but at the time didn't know which side of the engine the flywheel was on so Haynes instructions of "move the lever toward flywheel and tighten" meant nada! (Opposite end to timing belt, right? cos thats the direction the revs increase). I'll have a go at that later, though I've been told it probably doesn't work anyway!
Don't know the answers to my priming pump question do you?
David W
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Post by David W »

My own TD is in tip-top order and as an example of primer behaviour...
From overnight the bulb will squeeze about three times before resistance is felt. Even after that the bulb has a slightly squishy feel, you can squeeze it in about 20%.
If I leave the bulb for a further 20secs then it takes another few pumps to firm up again.
Sounds like yours may be normal.
Which fast idle system have you got? A cable to a waxstat in the coolant or a cable to a vacuum unit and an ECU?
David
RichardW
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Post by RichardW »

Mike,
I'm over here too....
Ref (Some of your questions)...
You will need to take the car for a run to get the full boost pressure - as you need to get it under load on full boost - eg up hill in 3rd at 3000 rpm [:D]
Flywheel end of engine is RH as you look at from the front, yes opposite the timing belt. I think you have been told right - if the cable is slack it's likely it is shot - should be easy to change though, and not too expensive. Mine is stuck the other way - always on fast idle.
I think the primer should stay hard - I think mine is - although some are fitted with a bleed valve that directs the diesel back to the tank once the air has been purged.
I don't THINK air ingress will affect performance/MPG - I had quite a bad leak on my old BX, making it very difficult to start, but once running it was fine, no loss of performance or MPG. My Xantia TD will easily reach 90, and returns around 40MPG - it gets driven quite hard! I suspect the timing belt needs doing, and the timing is out, resulting in poor consumption. Your 33-35 defo sounds below par.
Valve clearances not too bad to check - take the rocker cover off, and there they are - you probably need to jack one corner up to turn the egine over. New gasket will be needed on completion or it will leak!
Timing is a bit more difficult as you need to get the belt covers off, and this requires removing the RH (drivers side) engine mounting - support the engine with a trolley jack and block of wood under the sump. You will need to fabricate some sort of rod to insert into the flywheel behind the starter motor - access is very limited, unless you remove the starter. Note that just because the pins go through the injection pump sprocket, the pump timing is NOT NECESSARILY right! It works like a distributor, if you hold the shaft steady and turn the body you change the timing. To check this is right needs a dial test indicator and some other bits and pieces, so is best left to a specialist.
LHM - do you mean bright orange, or watery yellow - if bright orange then it is already hydraflush. If watery yellow, then it is old shot LHM that should be changed.
HTH
Richard
95 Xantia TD LX
Xantiargh
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Post by Xantiargh »

The cable goes into a silver bolt-type mounting under the fuel filter. The coolhant hose enters the front under the fuel filter so I assume the silver bolt-type thing is a waxstat.
I'm going to tighten the cable (the car is cold, lever is at timing belt end, cable slack) and take the car to halfords to buy some fuel hose, clear if I can find any. Hopefully that run should warm up the waxstat and I can see if it works or not.
Xantiargh
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Post by Xantiargh »

Damn, I forgot to tighten the cable so I'll have to wait until tomorrow to tackle that. Got confused by the different hose sizes in Halfords. I had delusions of standard size or one of their flip charts, but no. Parts desk didn't have a clue either so I bought the smallest diameter (5.5mm). (This is intended to replace bit from fuel filter to injection pump).
Driving to Halfords, the car felt pretty good. The performance seemed to tail off a bit as the engine heated up, particularly on the way back.
[non-mechanics illogical theory follows:][;)]
I've heard that some cold start systems advance the timing a bit to provide more power. I've also read that advancing timing = more power = more smoke. As mine doesn't seem to smoke at all, and power (possibly) drops off a bit as the engine warms up, could this indicate slightly retarded timing. Would this result in poor starting, say coughing for 5-10 seconds?
[End of theory]
I assume the cambelt belt timing and the injection pump timing are two different things, so if I pay to have the timing belt changed I still have to get the pump timing done as well, right?
The LHM was rusty green as far as I can recall. Def not bright orange anyway.
I wonder if its possible for this car to ever run how I think it should [;)]
Mike
Dave Burns
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Post by Dave Burns »

The priming bulb doesn't pressurise the fuel inside the injection pump except for the tiny amount while it is actualy being squeesed, nor will the bulb remain totaly firm, the small amount of pressure generated will disperse just as soon as hand pumping stops.
The reason for this is the outlet restrictor, the return pipe from the pump is attached to the body via a banjo union wich usualy has the word "OUT" stamped on it, this banjo union is also the return restrictor.
The restrictor has an apperture in it which allows air to pass freely but offers greater resistance to the passage of the liquid fuel due to its small size.
The restrictor has two main functions, firstly it enables the continuous purging of any air that gets in while the engine is runing and is also the escape route for any air when hand priming, negating the need for a seperate bleed nipple as on other pumps such as the Lucas, secondly it allows some fuel back to the tank while the engine is running and this serves to cool the interior of injection pump.
The fuel in the body of the pump is at differing pressures throughout the engines range of operating speeds, this critical pressure/speed relationship is maintained by a spool valve at the front of the pump, and is also matched to the outlet restrictor thus preserving the speed related pressure within the pump.
The timing advance is controled by the pressurised fuel acting on a piston connected to and able to rotate the roller ring, this is the reason for the critical fuel pressure as supplied by the lift pump.
Its not inconcievable that down the model years and due to continuous development that the size of the outlet restrictor and operation of the spool valve may have changed, giving rise to the different traits of the primer bulb.
But basicaly if you are getting a fair number of pumps before the bulb firms up then this is because of air going through the restrictor then firming up as the increasing fuel level also reaches it.
Dave
Xantiargh
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Post by Xantiargh »

Ta muchly for info Dave, you truely are a Super Guru [:D]
I've adjusted the waxstat cabling and what do ya know. It actually works, result.
The car started with no coughing today (after waxstat adjustment) but then it was warmer and the car was parked facing downhill. If it starts ok tomorrow I'll be well happy and not touch it until I get round to doing the brake discs...
Thanks for help so far David, Richard, Dave et al.
Mike
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