Idle fluctuations?

[JTaylor2005]

Alright guys. When cold my cars idle fluctuates up and down. Sometimes in a rhythm other times just randomly. When it warns up it seems to get a lot better but it's still there a bit :/

I spent an hour earlier taking the FPR out and cleaning it with wd40 and maf sensor cleaner (evaporates really quick so was okay to use and then washed with wd40 after)

Any ideas what it could be guys?
Cheers

[Toms306]

It's pretty common with them, several of mine did it, never did find a solution though so this is kinda pointless post haha.

[JTaylor2005]

Haha just seems odd. Wouldn't know where to start working out what it is tbf haha. Never mind will just leave it lol

[Toms306]

Well, I watched lots of live data on PP2000 with one or two of mine and couldn't find anything that caused it unfortunately. Maybe will Poodle or Steve know what causes it though.

[Poodle]

Knackered injectors, fpr, fuel filter, could be many things. Got a feeling someone found a solution to their issue recently, could be worth a try, have a browse through the recent threads in this section.

[JTaylor2005]

It's done it on two sets of injectors. The fpr has been cleaned out and tbf wasn't really dirty looking anyways and there is a new genuine peugeot fuel filter and also a new housing fitted recently haha. Confusing. I will have a look around would be nice to finally get to the bottom of it haha

[Redordead89]

I had a similar issue today with my 1.6 petrol where I started her up and the idle was fluxing between 600-1300rpm for about 5 seconds and dipped to 500 and stalled! First time it's happened in this car but not first time ive had this in a 306!
When cold start up it usually idles high around 1100-1200 for the first couple of minutes then settles!
Any ideas? I did a fair amount of engine bay cleaning last night so may have disturbed something!?!?

[JTaylor2005]

Wonder if the HDI issue could be maf sensor or voltage related? Its almost the same sort of fluctuation on mine as when for example I open the window. The initial surge of power draw causes a dip in RPM.

As for your issue Redordead it would be worth posting in the petrol section of this site. However if anything it would point to a problem with the idle control valve (if it has one) or a dirtied up throttle valve I would guess. That was often the cause of that sort of behaviour on other cars

[connorcarp72]

I have seen this a few time.try a continuity test on the fps harness (short peace of loom that connects the fps with the main harness) there's 3 green wires the one in the middle fails for some reason.never flags eml but creates idle issues.worth a try

[JTaylor2005]

Right. Well having put up with this for a while now a mate of mine asked about it when I was idling. I had a fiddle with what electronics I had on at the time. I turned the lights, radio, and fans off and the idle basically became totally steady. Just a very very slight movement on the needle. Do you reckon it could be the alternator or something like that?

[Poodle]

High load on the engine at idle could make it harder for the engine to maintain a steady idle if there is an issue, but shouldn't cause a problem by itself. More likely the high load is just highlighting the underlying issue.