Micra K12 rough idle choke issue?

[Deanyb]

Hello,

Ill give you all a quick background before I explain my problem. I own a Micra K12, 2004 (04 plate), manual 1.4 SE. It has 63000 miles on the clock and has been regularly serviced and well looked after.

I have been experiencing a strange issue recently. As you will know, when the car is started from cold the blue temperature light comes on. This goes off after about 4-5 minutes of driving.

However, when stopping at traffic lights or a junction very soon after the blue light goes off, the engine does not idle very well. The RPM's drop down to about 500, then jump back to about 1000 before settling ( I assume that is some sort of anti stall feature?). Occasionally the engine will stall.

However, this is the only time the engine does this. Other than this it runs perfectly and never misses a beat. It starts well regardless of weather, never gets hot in traffic, the MPG's are good (about 50-52) etc.

In my mind, I would put this down as some sort of choke issue? It seems very weird that it only does that soon after the blue light goes off, and no other time. Therefore is it likely to be a temperature sensor problem? I understand that there are 2 temp sensors on the K12, one which controls the temperature light on the dash and the other which controls the engine itself?

I would really appreciate some advice on this issue, as I don't know where to go with it. I don't want to replace the temp sensor if I am barking up the wrong tree!

Thanks in advance.

Dean