Misfire On Startup.

[terryds]

I have an itermittent problem with my 2006 1.6 petrol C3 and would appreciate any help you can offer. This problem only occurs on first startup when the engine is stone cold. Usually there is no problem but occasionally the engine starts with a misfire and feels as though it is running on three cylinders, after a short while the anti pollution warning displays which I assume is caused by unburnt fuel reaching the exhaust. This problem would persist if I didn't stop the engine. The strange thing is that usually when I restart the engine the warning light goes out and the engine runs perfectly. There are no stored fault codes. My wife is about to take her driving test and I would like to try and sort this out before she hits the road. I have changed the spark plugs but it made no difference.

[qman3428]

Not sure about the petrol engines but it sounds like the choke sensor is activated but not going off.

My thinking is that when you restart the engine it has warmed up so doesn't activate the choke and therefore you dont have the issue. This would tie in with your excess fuel theory causing the depollution fault.

[Praktoras]

There are various theories on this problem; have had it on my 2003 Xsara 1.6 petrol. I would start with the easy to check things; spark plugs and fuel pump. Especially if you park your car uphill and a bit leaned.

[paul.h]

It could be a faulty temperature sensor, does your code reader show live data so you can see what the sensor is indicating, the air inlet one (AIT or IAT), and the engine coolant one ?