Rev's stopping up.

Stuart McB · Post by **Stuart McB** » 15 Jun 2004, 21:02

Only a quicky. On a couple of occassions now I have noticed that my engine rev's stay high [:(] as though the throttle was stuck, around the 2K mark. If you stop the engine for a couple of mins it seems ok. Now as I say it's only happend a couple of times in about 3 weeks. I've been up to my local Citroen dealer who reckons it's the map sensor, but this was replaced about 12mths ago on a recall. All fitting seem OK and the temp gauge etc seems OK. No STOP light and no apparent high fuel comsumption. Dealer recons other possibles could be
1) temp sensor for the ECU
2) throttle potentiometer
3) speed sensor.
Model is a Citroen Xsara 1.6 (8 valve) 1998 VTR. Any info appreciated. I am going to give the throttle housing a clean to night as it may just be gunk on the butterfly.

tomsheppard · Post by **tomsheppard** » 15 Jun 2004, 21:59

I'd check for a little free play in the cable. It could be a little sticky.
Check the throttle pot is moving freely and that its spindle is solidly attached to the thing that turns it. It does sound as though it is not returning fully all the time. Have you tried blipping the throttle and letting your foot off sharply to see if that shows up lost motion in the linkage?

Post by **philhoward** » 16 Jun 2004, 00:52

If it was a Ford, it'd be the ISCV (Idle Speed Control Valve); does the Xsara have one? The fix is take it off and give it a damned good cleaning with Carburettor Cleaner.

Stuart McB · Post by **Stuart McB** » 16 Jun 2004, 01:39

Thanks for that about the speed control valve. That's what I meant when I put in number 3 about speed sensor but I couldn't remember the exacted name [:I]. Any how have taken the throttle body apart and cleaned it up nice. Checked all electrical plugs and contacts and sprayed some carb cleaner on to and in to (through a small opening)the speed control valve. Now the rev's have come down to about 1200 but this is still higher than the usual tick over over 850 + or - 50. Good news is the wife pointed out that it's still got warranty until 24.06.04 [:D]. So that's it back to the dealer tomorrow afternoon after work. And a hire car home. I'll let you know how I get on. And Tom thanks for your advice as well have, checked throttle cable and all in order. I did notice thought that the potentionometer didn't feel that smooth but hey what do I know I'm only mortal.

jeremy · Post by **jeremy** » 16 Jun 2004, 11:53

have a good look at the throttle cable - My wife complained one day that her ZX 1.9D stuck at full revs (hidden power?). Everything seemed ok but i decided to replace the throttle cable as this was the easiest bit that might be the problem. The cable has a lubricant in it and this seemed to have gone hard and granular. All ok now with the new cable.
Jeremy

uhn113x · Post by **uhn113x** » 16 Jun 2004, 13:15

Stuart
Try threatening him that you won't go to church unless he goes to bed.....[}:)][}:)]
Oh, I see. If fault cures when engine is stopped for a while, it is unlikely to be the cable or flutterby sticking. If there is an idle speed control valve this is the prime suspect, especially if it only does it when warm. I would have thought that a MAP sensor would affect mixture more than speed.
Mike (Deputy Apostropher Royal)[;)]

Stuart McB · Post by **Stuart McB** » 16 Jun 2004, 23:56

Thanks for all the replies. Have been to the dealer today and guess what? that's right the car has run fine since yesterdays throttle cleaning. Any how the dealer plugged in a fault code reader and as expected no fault codes to be seen, he tried all the plug connectors and doubled checked the throttle housing butterfly etc. But nothing to be seen, the dealer said to come back if the fault happens again so can't complain. As a precaution I have taken off the idle speed valve and given it a good clean. It was full of c**p but this soon cleared with that carb cleaner I bought. Have taken for a spin tonight and again all is well. Thanks for all the replies.