Xantia idel speed

juppy · Post by **juppy** » 02 Oct 2007, 06:36

My T reg 1.9 TD seems to be ideling too fast aprrox half a needle width over 1000 rpm even when warm. I have tried adjusting the nut/rod at the back of the pump as stated in Haynes but it seems to have no effect, does anyone know what i might be doing wrong?
Thanks,
Garth

Post by **CitroJim** » 02 Oct 2007, 07:40

I'm sure MikeT won't mind,

Have a look at this Garth. All is in here

http://www.frenchcarforum.co.uk/forum/v ... hp?t=22760

MikeT · Post by **MikeT** » 02 Oct 2007, 08:20

Hi Jim, I do mind as it happens, that thread is sooooooooo confusing

Garth; In short... the default pump setting is fast idle. Once the engine gets warm enough (ignoring Air-con for now) the ECU operates an electrovalve which allows vacuum to pull a cable at the rear of the pump. This cable pulls against the fast idle spring-loaded mechanism, setting the idle to "normal".

From reading this forum, it seems the electrovalve is the most likely suspect and fails to operate when activated.

HTH

juppy · Post by **juppy** » 02 Oct 2007, 20:50

Thanks for the info guys, however where do I find the electrovalve? Also I have noticed it is reving even higher than it used to now i am running on 50% veggie, is this normal also my mpg is down! from 44 to 40

MikeT · Post by **MikeT** » 02 Oct 2007, 21:21

There are two electrovalves (on mine) side by side fitted to (or bracketed on to, can't recall now) the bulkhead between the LHM tank and the engine. A vacuum pipe comes from the vacuum pump situated on the end of the crankshaft. That pipe goes down to the electrovalves into a t-piece to feed both.

Personally, I cannot relate idle changes to using veg oil. Perhaps it's because you altered the idle as per Haynes?

Some say veg oil increases mpg, some say it decreases it. I haven't done a scientific test myself but at almost half price, it has to be a huge difference for me to care

MikeT · Post by **MikeT** » 03 Oct 2007, 17:46

Well I decided to have another look at my fast idle system today and after removing the airbox and first induction pipe, you can clearly see where the the two electrovalves are located.

But I then discovered a third in/outlet underneath each valve which in the default state, passes atmospheric air through to the device it's attached to (fast-idle or EGR).

Is this proper? I'm guessing it's to release the vacuum once the electrovalve is de-activated and is blocked off when activated? I haven't been able to test this yet and if the electrovalve has failed I won't be able to anyway.