Xsara HDI 90 Accelerator doesn't respond

Hoo · Post by **Hoo** » 24 Aug 2010, 21:56

Hi, can anyone help with this? I have an intermittent fault on my 2001 Xsara HDI 90 BHP. It will go for days without happening, then once or twice on a journey.
When the car is idling, I'll press the accelerator and nothing happens. Yesterday I sat at traffic lights in neutral with the accelerator down about three quarters and held it there, and the car sat there at idle. After about ten seconds the revs started to rise quickly, and at about 2000 I lifted my foot and from then on it drove fine. It only seems to happen at idle, I've never noticed a loss of power while moving. Holding the accelerator down or pumping it makes no difference, I just have to wait a few seconds and it starts working again.
It will also cut out occasionally, but again this only happens at idle. It always starts again fine afterwards.
I had a garage look at the fault codes, but they say they didn't find any that were relevant. They couldn't reproduce the fault.
It's done 165k miles, so getting on a bit. Oil, fuel and air filters were changed recently.

citroenxm · Post by **citroenxm** » 25 Aug 2010, 10:19

HDi Throttle pedals are NOT connected to a pump or engine directly!!

They are connected to a "Throttle Potetiomter" - which can be found over around the Air filter house..

It sounds to me this could very well be playing up, or the air flow meter.. as the HDi is just like a Petrol injection engine... it measures air flow and throttle position to determind how much fuel to put in...

Paul

Hoo · Post by **Hoo** » 25 Aug 2010, 10:52

@citroenxm

I'm aware of the throttle setup, I've checked the connections to the potentiometer. The trouble is that the fault is so occasional that I've never been able to check it while it's occuring.
I would suspect the potentiometer, but why is it only on idle? I'd expect it to lose power sometimes while moving too. Also, if it was a dodgy pot, pumping the pedal should make it work again.

Does idling require the air flow meter, or is another mechanism used? Nothing happens when I press the accelerator, but it's idling OK.

citroenxm · Post by **citroenxm** » 25 Aug 2010, 12:43

i take it your Manegment light is NOT lit up either???

If you were near someone with a Lexia diagnostic, with that connected you can measure ALL paramiters in the engine bay..

I had someone in a xantia HDi 110bhp with this same problem, however, after a while it cleared itself completely, so I never investigated the problem

Paul

Hoo · Post by **Hoo** » 25 Aug 2010, 14:20

That's correct, no warning lights, and the garage said there were no relevant codes. They're just my local garage, not a Citroen dealer. I don't know if they'd be using a Lexia or a generic fault code reader.
I'm in West Sussex (added my location to my profile now), how do I find out if there's a Lexia owner nearby?

Post by **myglaren** » 25 Aug 2010, 15:50

Take a look at this map and PM the member closest to you.
Takes a minute to load fully.

cachaciero is practically on your doorstep