406oc.co.uk

Since having my car for two weeks now and a good 700 miles its done a little quirk twice lol.

When sat in traffic (Once in queue for mcdonalds and once in slow moving traffic for 5-10 mins) the idle will increase to 1200rpm and fluctuate slightly down to 1100. It kinda sorts itself out once moving. I thought I originally cured when I loosened the throttle cable after tweeking it. But its done it again so I doubt its that.

Is there an idle valve or something which needs cleaning?

Maybe lambda sensor, also take a look here

Should I have said its for the 2.0 90hp HDi as that seems mainly for petrol?

Yes I think that's all irrelevant to you!
Have a search on Mass Air Flow meter, there were some posts not too long ago regarding this on the HDi; also EGR valve.
Sorry I can't be of more help!

Have a wiggle of the electrical multi-pin connector on the throttle position sensor (the one the accelerator pedal cable goes to) for some reason you sometimes get a bad connection here causing a high idle. Mine did this on my 110 but should be same principle on the 90.

Let us know.......

Ill disconnect the plug tomorrow and check the pins and spray some WD40 in there and see how it goes

Still got the same problem...

Just judders a bit and then hits 1200rpm and then by itself it will drop back down to 800 ish... then judder a few minutes later and revs climb to 1200rpm...

Weird...

Ive disconnected the plug and wd40 it and still the same...

How annoying...

Surely must be a cure

Do the HDis have a fast idle gizmo like my TDi? Mine is broke you see, so it's stuck at the fast idle speed.

Ive disconnected the MAF assuming it could be that... But after a short journey the revs increased to 1200rpm... then drop back to 800 then climb to 1200 again...

swiss wrote:Do the HDis have a fast idle gizmo like my TDi? Mine is broke you see, so it's stuck at the fast idle speed.

No, in fact they don't really idle faster when cold. The HDi uses 'fuel enrichment' by the ECU when cold.

I can only suggest a duff throttle position sensor really. I don't know what else could cause this?

These might help?
http://www.ilexa.co.uk/forum/index.php/ ... 084.0.html

I do have a DTC stored for throttle posistion sensor... I can erase it but it comes back instantly...

How many throttle posistion sensors are there on the car?

1 Pedal and on the accelerator cable box?

Is there a way to test them?

Just the one on the end of the cable, not sure how you test it tho

As far as I know the pedal just pulls on the cable and the throttle pot up on the right hand behind the battery.

I had a receipt from a Peugeot dealer with my car for a new one at about £60.00.

I think the problem arises from interferance from a worn track inside the unit giving weird readings to the ECU. Years ago dealers used to separate the earths from the MAF and T.Pot to stop spurious faults popping up all the time - something I learnded from that there website above.

I see,

I guess the simpliest and cheapest fix is to try the earth mod? Can you shed some light on it welly with pics/how to?

Is it possible to disassemble the throttle pot and clean etc?

BruceT wrote:I see,

I guess the simpliest and cheapest fix is to try the earth mod? Can you shed some light on it welly with pics/how to?

Is it possible to disassemble the throttle pot and clean etc?

I'm affraid I don't know, it was something I read about on that diagnostics forum above.

I suppose you can get inside the unit with care even though you're probably not suppose to be able. I guess it's like a variable resister on some kind of electrical track?

Why not grab one from a scrappy and then have a play (so you at least have a spare if it goes wrong).