Fiesta 2009 Idling Problem

Phemo

Phemo

Phemo

Soldato
Joined
6 May 2004
Posts
6,071
Location
Fareham
Hi guys,

I'm having an issue with my car not idling correctly which is a bit irritating as I'm getting rid of it shortly but before I do I should get this sorted out. It's a 2009 MK7 Fiesta 1.6 petrol with just under 69k on it.

Basically the engine would normally idle at around 800-900rpm after starting up but recently it's started behaving weirdly. Now it'll initially hop up to around 1100rpm at idle and will then start jumping around all over the place. Sometimes it'll jump up as high as 1600rpm then back down to 1100rpm and other times it'll go down below 900rpm. A couple of days ago when it was cold it dipped down low enough to stall itself though that's only happened once.

After I've been driving for 5 minutes or so the problem 'vanishes' and it idles at the usual 800-900rpm. When the car's actually on the move there are no other problems - doesn't appear to have any loss of power or shuddering etc.

The car was serviced a week ago and me being the idiot I am forgot to mention this fault when I booked it in.

From doing some reading the common causes seem to be engine idle control valve, spark plugs and dirty throttle body.

I can't seem to locate the engine idle control valve at all but some people seem to think this is located in the throttle body. The spark plugs were changed when it was serviced and I've just taken the throttle body off to take a look at it and it was surprisingly clean but I've cleaned it up a little more anyway.

So, does anyone have any suggestions?

Cheers.
 
Any error codes? Check for leaks in the air intake stuff, bit of carb cleaner sprayed around joints and listen for a change in revs. You can also try disconnecting the maf to see if there is an improvement.

So is it only when the engine is stone cold?
 
I'm not getting anything flagged up on the dash and I'm not sure how else I can check for any errors without getting the OBD hooked up which I'll see if I can do. I'll try disconnecting the MAF.

I thought at first that the problem is only when the engine is cold and 99% of the time this seems to be the case. However the other day I drove from Basingstoke to Reading (17 miles or so) early in the morning when it was a lot colder than usual. I parked up outside a friend's house, waited for 5 minutes then started up again to move my car to his driveway and it was then that it stalled.

Normally I can start the car up within an hour or so of having driven it and it appears to idle correctly. So, it seems to be either when the engine is cold or when the weather is particularly cold but that could've been a one off as it hasn't stalled at idle since, but then I haven't driven when it's been as cold since. Thanks for the suggestions.
 
Apologies for resurrecting an old thread but just thought I'd update this. The problem got a lot worse with it stalling very regularly, pretty much every time I came to a roundabout or some lights so it was very annoying to say the least, especially when sitting in traffic. I took the car into a garage twice and both times was told that they couldn't find a problem because no fault codes were showing up.

It turns out that on this car the idle control valve is indeed part of the throttle body so in the end I decided I'd had enough and thought I'd just take a gamble with another throttle body for £40 off eBay. It seems to have done the trick :)
 
Phemo said:
Apologies for resurrecting an old thread but just thought I'd update this. The problem got a lot worse with it stalling very regularly, pretty much every time I came to a roundabout or some lights so it was very annoying to say the least, especially when sitting in traffic. I took the car into a garage twice and both times was told that they couldn't find a problem because no fault codes were showing up.

It turns out that on this car the idle control valve is indeed part of the throttle body so in the end I decided I'd had enough and thought I'd just take a gamble with another throttle body for £40 off eBay. It seems to have done the trick :)
Click to expand...

£40 for a throttle body! Mine is over £300! Very rare for a throttle body to go wrong on a 2009 car.
 
Phemo said:
It turns out that on this car the idle control valve is indeed part of the throttle body )
Click to expand...

The throttle plate is 100% ecu controlled so it is the actual idle speed controller. A clever system, it does away with an ICV altogether - a bit awkward to snap the throttle under the bonnet though :D
The garage in question may not have had any codes, but they should have looked at things like desired/actual throttle angle information via the scan tool. AFAIK No Throttle has a base (closed) angle of 0 degrees as it wouldn't let any air through at idle. IIRC it will usually be around 5-8% on/just off the stop, a little higher when warming up.

Did the old throttle have any carbon or dirt buildup by any chance?
 
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Brookert said:
£40 for a throttle body! Mine is over £300! Very rare for a throttle body to go wrong on a 2009 car.
Click to expand...

Yeah I thought it was pretty decent. To be fair a brand new part from Ford is £270 I believe but used ones from stripped down cars tend to go for anything between £40 and £90 from a quick skim around so I got reasonably lucky. Although the car's only 3 years old it has now covered 77k. Not sure if it's more normal for this kind of thing to fail with age or if the mileage plays some part.


MatteH Oxford said:
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Did the old throttle have any carbon or dirt buildup by any chance?
Click to expand...

Thanks for the explanation, makes more sense now :) The old one actually looks reasonably clean so I'm pretty confused as to what went wrong with it exactly. There's a little bit of muck in there but I've seen far worse before. It's bizarre but then my knowledge of these things is pretty limited.
 
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