Hi again,got the intermittent idling,usualy just after starting up,it will rise to 1500,drop to 500,up and down a few times and will stall,not sure if it cures the problem but usually goes away after ive had to restart the engine a few times.frustrating thing it dosent do it all the time so hard for garage to see what is going on.
Ive took the throttle bodies of and cleaned them,cleaned the Maff sensor,ran a couple of tanks of the better petrol threw her.
Ive read all the posts and not sure if its different but when i start the car up and the idling is jumping there is a A STRONG SMELL OF PETROL,havent read about smelling petrol from other posts.
I have changed the air filter to the K/N one,last week put the standard one back in to see if that was the problem,was running smoother for a week with no idling and thought it was sorted but came back,so put the K/N filter back in as it sounds better.
I have just put a bottle of redex and filled up the tank,going from London to Portsmouth today and back tomorrow,im thinking could be the fuel injectors causing the problem so hopefully a good run out with the redex in it will give them a good clean out[i know some peeps say not to use it]
any thoughts and ideas greatly appreciated
cheers.
Any help ideas would be greatly appreciated.

 

What Fiesta exactly is it ?

could be an air leak.

 

sorry 2011 fiesta zerec s,59k on the clock,frozen white,love the look and the drive

 

well im back and so is the idling,going to book it into a diagnostic centre next week to see if they can get to the bottom of it,will post up any findings

 

Im back,been in the garage and all tests come back clear,no leaks,no hidden error codes,didnt miss a beat when in garage.
Bought a new air mass sensor and it still done it,lucky sent it back and got a refund,checked a spark plug and could do with a change,going in next week for a full service.
When i take the car out for a sunday blast it dosent miss a beat,mostly only does it when in town.
I remember when i first got my kawasaki ZX6R,after a week i was passing the shop and called in,was telling him it seems a bit lumpy and rough and he asked me how i was riding it,i told him just normal,he said no,its a sports engine,ride it like u stole it,i did and it was a completly differant machine and all made sense,the bike loved it.
I told the wife that and that if she was in 3rd gear,then 2nd gear will be better and dont be scared to keep it in 2nd,[be like girl racer]not rev the nuts of it but keep the revs up higher than normal,that was 2 days ago and the car hasent stalled,idled badly at all.will likely use a bit more petrol but so what.
So im thinking,16L Zetec S engine shouldnt be driven around like an old persons car and needs to be used and abused a bit.
Only time will tell i suppose.

 

still intermittent but nowhere near as much until,was taking the airbox out today to drill six 12ml holes on the side facing away from the engine and taking out the internal snorkel,whilst i was doing it,never even noticed it before but when i went to take the crankcase vent hose off,it just pulled off very easily,pushed it back on to i heard the click,then took it off again which needed a bit more force,so i dont think it was on properly in the first place which could have been my problem all along[hopefully].
result,the car has a nice little bubbling note at idle,when u gun it its got a lovely noticable but not to loud induction note,a lot more fun to drive.
idles been sitting steady at 7500 and has been fine all week,will give it another week to make sure,fingers crossed.
had a js performance induction hose on the car,bright red,but went back to standard hose after airbox mod,so looking to get rid of it for a small fee ofcoarse,anyone interested hit me up.
cheers

 

A common problem on these engines is the idle speed cntroller gets clogged up with dirt.
These are easy to remove (2 8mm bolts). Once you take it off, give it a good wash with brake cleaner spray.
One of the reasons for it being intermmittent is due to the heat from the engine loosening up the dirt in the valve, (only for the issue to retrn when the engine is cold).

Thank fully you may have caught this issue when it was begining to start - Meaning you havent completley wrecked the part.