specalist knowledge in 1.9TD xantias and idle speed.

[RichardW]

Ah, so it appears that the problem with the super fast idle is not the fast idle, but in fact the throttle. So you need to establish whether it's the cable or the pump that is fault. Get it hot so the idle is high, and then release the adjusting clip on the cable to see if the throttle returns, which will point to the cable or the pump. For the avoidance of doubt you could remove the pot on the top of the pump. Does your car also have the black shock absorber looking throttle damper on the front of the pump? I recall that these can be a source of trouble - try popping it off and see if that improves things.

As I remember (although it's a good number of years since I played with one!) the cable being taught when cold and slack when hot is right. If you switch on the AC then you should see the cable tighten up. Once the engine is warm, then you should be able to push the fast idle lever on the back of the pump (to the right as you look at it) and the engine speed should rise. As Jim says, if the system has not been working properly, then someone may have screwed the stops up or down to try and set the idle speed.

I do remember that adjusting the cable is a 3 handed job though! You need to back the clamp off, then push the lever to the right against the spring and hold it there, whilst pulling the cable tight AND tightening up the screw!!!

So, I would make sure the throttle is free, then adjust the fast idle stops, first with the engine cold and then hot to get the correct idle speeds set, then you can figure out whether the fast idle is working right or not.

[Harlequin]

heya - mine is very similar (in the respect it doesn't come off fast idle); I'm leaning towards the electro valve - how can I bypass it direct to the vacuum to see if the diaphragm is working?

[RichardW]

Disconnect the hoses off the vac valve and connect them directly together.

[falling-out-with-my-car]

That's me Jim Unskilled at this one I'll have a tinker but I don't fancy
my chances at getting it right, to my way of thinking it should
be possible to slide the plate the diaphram sits on left to right
but I cant see any room for adjustment unless you can adjust the cable
at the linkage with the pump which is hard to see on my car with so much gubbins in the way.
as with Simon above Im also leaning toward a sticky electro valve perhaps when it gets super hot
from rising heat, it is difficult to know which valve is faulty though, as I have two of them side by side.
I'm going to try the above to see if the diaphragm is definitely working as this should achieve fast idle
when the engine is cold something that it does not do at present.
as the fast idle at cold does not work it would seem to make sense to disable the whole diaphragm thing altogether.
The engine has not been used to being at fast idle when cold for years.
would it be possible to disconnect the diaphragm vacuum supply effectively taking the diaphragm out of the vacuum circuit
and just not run the diaphragm at all
or would this muck up the idle even more? perhaps this would point to a faulty pump if the pump was at fault?

[CitroJim]

Nigel, if you really get stuck then perhaps in a couple of months time I'll have an opportunity to look at it for you, else if you're attending any rallies this year I could maybe take a look then...

[falling-out-with-my-car]

Jim,
Thanks very much, I will however try to get my head around a diesel pump if I can.
I find learning quite difficult these days to many painkillers on board I'm afraid.
Give me a carburettor any day its easy to set one of those up.
Ive always been a little frightened of diesel pump adjustment I don't know why I just have.

[Harlequin]

which pump is it? mine is a bosch and I can manually move the fast idle (its on the back on the pump ofc) - mine drops to lower revs with the me manually moving the cable , but ofc returns back to fast idle. I think its either the diaphragm not working for the valve not working .

will check tomorrow when I have a day off

[falling-out-with-my-car]

as I have two electro valves is it at all possible that I have the wrong valve connected to the
diaphragm effectively operating the fast idle in reverse?
does anybody know what the second electro valve does?
Mines a Bosch to Simon.

[CitroJim]

The other electrovalve operates the EGR valve Nigel...

[falling-out-with-my-car]

Thanks Jim,

I found this thread from 2007 with a lot of helpful info in it to.
http://www.frenchcarforum.co.uk/forum/v ... hp?t=22760

[RichardW]

Can you post a pic of the pump? I'm not familiar with the later ones, might help to visualise it. However, if it's got the black damper on the front, disconnect this first - I'm>90% sure this will fix the high idle when hot. Rest we can work on....

[Goc3k]

The solution is already in the thread for certain - these guys really know their stuff.

I'd try RichardW's suggestion about removing the black damper on the front of the pump first if you have one, I had very similar problems on my 1.9td'd pug initially, throttle / idle fine when cold, idle too high / sticky throttle lever once engine had warmed. it's a simple thing to try, 2 minutes at best. No need to adjust anything on the pump!

[Harlequin]

thankmyou chaps - after bypassing the electro valve and connecting directly to the vaccum the revs dropped instantly

can the electro valve be repaired or should I start a mission to find them(main dealer cant get 1)

[CitroJim]

Unlikely to be fixable sadly but a scrapyard should be able to supply a few... They're not unique to the 1.9TD... You may even be able to adapt one from an HDi engine... They have two, one for the turbo and one for the EGR...

Got to be worth an experiment...

[falling-out-with-my-car]

I to am now fairly sure the electro-valves are intermittently dying.
Because of this the diaphragm is also unreliable, sometimes it works dragging the throttle down and sometimes it doesn't.
Not many yards have xantias on these days, fortunately the price of scrap at the moment will make them hang on to
the metal until the price rises a bit.