T5 Overfueling on tickover when really cold

[merc85]

deffo sounds like the temp sensor, was it a new one?

[Biff]

When my car was over fueling & idling rough I changed the maf & fixed the fault. It didn't bring any codes up.

[nobananas]

Could be ect sensor, if you can get live readings before the vehicle is started from cold and it's reading massively lower than the outside temp then it's a likely culprit, also won't throw a mil.

[thewatsonsmouts]

I agree mass air flow sensor for defo be carefull as you may blow your cat up !!!

[Pinchcliff]

Thanks for the comments, really helpfull, just came back from Ireland on a 800 round trip, car ran like a dream (32MPG overall) other than the cold start overfueling for around 2 mins, again only when really cold (in Ireland it's really cold all the time in March). I realise it may be a problem for the cat, plan on putting the new MAF on tomorrow morning.

[Pinchcliff]

Just fitted the MAF, hard to see if there is any inprovement as is around 6 deg, the problem seems to occur when it's 3 deg or less, however the car runs great with the new MAF so fingers crossed. One question though, the old one had a metal gauze on the airbox side, the one I've fitted doesn't have this. I can see how it's removed but the new one doesn't have the bend over tags on it. Does it really make much difference?

[britten_mark]

Did anyone find any conclusion to this issue? The description was so like my car I thought it was an ancient thread of mine.

basically I have had this car for 3 years, each winter when the overnight temps drop below 3 degrees the car "hunts" on startup, quite violently sometimes, you can see the headlights dimming and brightenning and the whole car shakes. Unburnt fuel spits out the exhaust and blackens the garage door.

Three seconds on the throttle and all is OK again, no excessive fuel consumption, nothing untoward except a nagging worry that all that unburnt fuel is killing the cat

AFAIK the ETM has not been changed but then I don't have full history on the car (purchased as one owner vehicle at 40k miles now on 80k). I've never checked to see the colour of the label as I wouldn't know where to look.

To my non-expert ears this would be a temp sensor or MAf fault but no codes have ever shown up. As I bankrupted myself chasing down "Lambda lights" on my old 850 yeasr ago and eventually fell out of love and sold it, I have up to date just decided to live with this, but it is a nag that it is another one of these "common" problems that doesn't have a consensu of opinion on a cure.

So there you go, do we have any more knowledge than 3 years ago?