XSARA intermittent poor running??

OzRX4 · Unread post by **OzRX4** » 02 Aug 2009, 13:04

Have a 1998 Xsara 8v 1.8 XU7JP engine, that is displaying intermittent shocking running with NO power above 3oooRpm..
6months ago, when rather warm here the car had a few times where it wouldn't rev above 3500 and if it did, only on flat ground. It had absolutely NO power at all and would hesitate and faulter at the slightest hill.
S/H MAP sensor fitted, all contacts cleaned, new plugs, Coil.
It's been Ok until last week, problem returned. Checked it over toady, found #2 plug lead slightly ajar, rectified that. Checked MAP vacuum hose, all clear, no blockage anywhere.
I read this thread this morning and was motivated to go and have a good look, but forgot to actually clean the MAP sensor. I did clean the idle sensor at the front of the throttle body and made sure it was all functioning correctly.. This seems to have tidied the idle somewhat as that it doesn't search for a good level as it used to.
We thought it was OK. Drove home, first 10 minutes relatively OK, then at a moderate hill all power was gone again and had to virtually coast to the top.
The possible solution in previous episode had been suggested that the engine temp sensor for the EU maybe faulty. This might be something I need to look at further as it'd explain it getting worse as the car gets closer to operating temperature?
I am looking at new leads tomorrow as just somewhere to start so I eliminate all possible problems. The car is at about 140,000km or so i think. Then it's possibly onto the temp sensor.
With a new coil and known good S/H MAP I'd doubt it would be either of those and I have done the plugs.
it's just puzzling it came back after 6 months.
More later

falling-out-with-my-car · 02 Aug 2009, 13:24

we recently had the same problem on a peugot and it wasn't the Map sensor all was fine until the engine warmed up when suddenly it was impossiable to acelerate, then the running of the engine bacame very erratic. the engine once swirtched off would'nt start again until it had cooled down in fact it was getting harder and harder to start progressively.

Peugeot mechanics said that it was something to do with the vacum advance sensor chip in the peugeot this was mounted behind the brake servo. we tried several second hand chips and ended up with one from a citroen ax 1.0 litre. the car started ok but still displayed the running problems once warm. it would feel as though it was starving of fuel.

Being as it ran smoothly for 10 mins we put it into auction in the end and it fecthed a good price. no one test drives at the auctions it just has to run.

I shall be watching this thread carefully as it would be good to know what causes this problem, sorry I can't be of any more help.
It might be worth you posting this on the peugeot section to see if anyone has had a similar problem esspecially as citroen and peugeot are the same company.

regards Nigel.

OzRX4 · Unread post by **OzRX4** » 02 Aug 2009, 13:39

Thanks for that falling out. Already had posted it in the Pug section.
I know of no such sensor that you speak of. Did you actually see this sensor?

falling-out-with-my-car · 02 Aug 2009, 13:46

oh yes it was mounted with two 8mm nuts behind the brake servo on the Pug. hidden from view.

regards Nigel.

OzRX4 · Unread post by **OzRX4** » 02 Aug 2009, 13:49

I'll have a look tomorrow in better light, 11pm here now and rather cool out.

OzRX4 · Unread post by **OzRX4** » 07 Aug 2009, 07:39

Had a mobile mecnahinc out on Thursday as the car ran so poorly i couldn't drive it up the driveway and onto the street

There should be a couple of embarrased specialists around IMHO.
It was the fuel regulator and I am sure in my fading memories I recall mentioning an anomoly I had found with fuel pressure in that if you restrict the return line out of the regulator, the car would idle almost perfectly. Nobody listened and no-one checked the fuel pressure until this mobile bloke did. Well what do you know.....pump was excellent but fuel pressure at idle was shocking, even worse with vacuum line disconnected to the reg. Well, replaced it with generic regulator and what do you know, it's been perfect ever since. AFter 6 months of Sue driving nervously whenever the car would cough/hiccup we now have a Xsara that runs better than it ever has. I'll admit the fault was intermittent and I'd bet it's been that way for years as the PO had the car to aworkshop 2 times for poor running where they cleaned and claimed to clean things the car doesn't even have

yet no mention anywhere of a fuel system pressure check.
I've been told for years to check ignition/spark first. This time I had replaced plugs, leads and coil with no result. My advice check everything, starting with anything NOT connected directly to the ECU in that there isn't likely to be a fault recorded as it's not connected to the computer.
One happy

home mechanic here

Unread post by **CitroJim** » 07 Aug 2009, 08:14

Excellent result

I must confess that would have been one component not to arouse much suspicion. They're normally pretty reliable nowadays and mechanically they're quite simple and straightforward with little to go wrong in them.

It's certainly worth bearing in mind whenever poor running does not have any other obvious cause.

Thanks hugely for posting the soloution

OzRX4 · Unread post by **OzRX4** » 07 Aug 2009, 11:48

Yes, me either Jim. Just one of those thoughts I suppose.
I knew as soon as I pulled the regulator out of it's little snug hole that it was the problem. It'd been out at least once before due to the slight visible damage on the plastic inner section of the reg itself.
Makes you wonder just how long it had been faulty or why I didn't see it mentioned as checked at any stage. It may have even been a replacement as it's a weber and the Xsara is Marelli injection?