Stalling Xantia

hamster · Post by **hamster** » 25 Sep 2008, 22:02

My petrol Xantia has started to play up when the engine gets warm.
its fine when its cold and when the engine warms up it runs fine.

However, once the engine is warm if I stop the car for a few minutes, say to go in to a shop, and then start it up again it won't tick over with out stalling. The only way to keep the engine going is to keep my foot on the gas which proves a bit arkward when trying to drive through town etc. once the engine has run for a few minutes its fine again.
obviously the engine will have cooled slightly while I've been in the shop but only by a few degrees I would of thought.

Any ideas what the problem may be??

Also sometimes when the engine has bee running fast for a while such as on a motorway when i then come to stop and drive slowly the engine will idle at anything between 1000 and 1800 rpm which makes driving through traffic a bit jumpy. could this be related to the previously mentioned problem?

addo · Post by **addo** » 25 Sep 2008, 22:16

Assuming it works, what's your temperature gauge saying? I take it you've checked coolant level recently with the motor cold.

Irregular running when warm - if it's a 16V, might be coil packs. Does it run smoothly once you bring the motor speed up?

Regards, Adam.

hamster · Post by **hamster** » 25 Sep 2008, 22:50

Temperature gauge reads normal. 80 - 90 degrees. I haven't checked the coolant level recently. Will check that tomorrow.

As I said the engine runs and pulls fine even when warm until I stop it for a few minutes and then start up again and then it just stalls as soon as i take my foot off the accelerator. If I keep my foot on the gas then it runs fine. After a few minutes of driving or keeping the revs up it starts to behave itself again.
Drives and pulls fine the rest of the time. Not noticed any change in fuel coansumption, got 35.5mpg out of the last tank.

wheeler · Post by **wheeler** » 25 Sep 2008, 23:03

Sounds like a sticking stepper motor to me, its deffo worth taking it out & cleaning it & the housing it sits in.

addo · Post by **addo** » 25 Sep 2008, 23:06

If you had a spark issue, then it's highly likely that economy would have suffered. Your consumption sounds similar to mine, though (29-30MPG on a good run

) so I don't think the problem lies with ignition or coolant temperature.

Other sensors/fitments to check for intermittent problems would be the idle stepper motor, TPS, CAS (perhaps this one first - look for intermittent operation or a bad connection). I doubt the MAP sensor is a contributor to your condition. One fellow recently had massive corrosion on his ECU terminals, so that is something else you could check if the battery's off.

Regards, Adam.

_kid_ · Post by **_kid_** » 26 Sep 2008, 00:01

i agree with the stepper motor cleaning. my old xantia 1,8 16v did this sort of thing, occasionally stall, sometimes fine sometimes idle to high/ sometimes ok. I cleaned the stepper motor and everything was perfect re idling.

As a first call i would remove the stepper motor (it should have magnetti marelli on it) clean it and all associated pipes and airways and see if that makes any difference, plus it’s the cheapest option.

newmezuk04 · Post by **newmezuk04** » 26 Sep 2008, 19:35

Those symptoms sound very similar to my oldd zx 1.4 petrol, it was down to an air leak (?).

hamster · Post by **hamster** » 14 Dec 2009, 19:14

following the last post on this subject the car sorted it self out and behalved for a while. The same problem occured in the summer a couple of time but then went away again for a few months and has just started again.
It doesn't do it every time but its now getting a bit annoying especially as its cold and i just want to get in the car and drive.
Also HWWBO keeps nagging me to get a better car as she's not keen on the xantia as she wants me in something flashier but I keep convincing her its fine and no need to get rid so want to keep it running fine!

Post by **xantia_v6** » 14 Dec 2009, 20:26

I think it is most likely the stepper motor, but it is worth a try of disconnecting the battery for a couple of minutes to reset the ECU.

hamster · Post by **hamster** » 15 Dec 2009, 14:13

where willi find the stepper motor? it isn't in the BOL as far as i can see

Sid_the_Squid · Post by **Sid_the_Squid** » 15 Dec 2009, 15:27

On the 16v the stepper motor is in the throttle body block (terminology fail), take the whole throttle body thing off give everything a good clean, that area and all the little vacuum/breather hoses can get a little clogged. also check for air leaks from split hoses. My 1.8 16v had an idling problem, similar to the one your describing, turned out to be one of the breather hoses loose connection leaking in air past the throttle.