Xantia Petrol - intermitant high idle speed ?

[Mandrake]

Hi All,

My Xantia has developed a habit in the last week of idling too fast while hot sometimes. After a normal drive that brings up the engine to normal running temperature I notice that when I stop the idle sometimes wanders up to 1200rpm or so and hovers around a bit then returns to the normal level. (800?)

This seems to be sporadic and intermitant, although I have only noticed it in the last week.

I also notice that performance doesn't seem as good as Dad's Xantia (both have the same 2 litre 8 valve petrol engine) and ever since I have had the car I've struggled to reach 10Km/litre in around town driving. Last time was only 8Km/litre. (although there was a signficant amount of idling doing suspension sphere changing, LHM changing etc in that tank of petrol....)

I'm guessing that there is a dodgy sensor on the engine anywhere, any ideas anyone ? There is probably no one local who could connect a diagnostic tool to the ECU.

Regards,
Simon

[AndersDK]

Simon -

Your dad will know that no matter it's an old style carby or later type ECU controlled engine - it's much the same issues when looking for poor mileage from anyengine.

First off : you will be surprised how heavy your acc foot really are
Then of course the standard service items have large influence - as you already know.
Not using super traction (driving low tyre inflation) ?
The 8V engine is a nightmare to time on the cambelt - as the crank pulley can/will slip on the rubber damper making the timing index hole a really bad joke.

The unstable idle I suspect would be the MAP sensor - contributing to bad mileage too.

[citronut]

or maybe an air leak in the induction on one of the vaccum hoses,or cold start device all bunged up eithj carbon
regards malcolm

[Gregg1100]

Hi,
I get this every so often. In my case, it is the crankcase fumes from breather at top of engine, running down pipes and fouling STEPPER motor. I just remove stepper motor, and clean it out with carb cleaner, and the cavity that it sits in. I also remove potentiometer and clean that out too. Also clean out all the pipes. I have still to get around to put a filter between the breather pipe and stepper motor body.
If your car is P reg and newer, the MAP sensor is different to earlier ones. Mine looks just like an oil pressure switch. The guys at local Citroen dealers say that they have never sold a map sensor, nor have any other local dealers. Obviously not a thing that goes PHUTT.
My car is a 97 Cit Xant 16v 2ltr VSX
Another thing, this car was horrible to drive--jerking, revving. Turned out to be inlet manifold gasket leaking at ends. New gasket cured it. Just get a little revving as mentioned .
Hope this helps,
Greg