Cold start problem on C3 petrol.

[Patt]

Hi, my 1.4 8v C3 has aquired a cold start problem. Briefly, it misfires, or at least runs very unevenly,for the first 30 seconds after a cold start. It then smooths out and runs normally. Any attempt to accelerate makes it worse during this time.
I have replaced the coolant temperature sensor, just in case, but to no avail. Anyway it runs so well apart from this.
Any ideas please??????????

[Lighty]

Water temp switch would have been my 1st thought, perhaps you could plug into a diagnostic, and see what the ecu thinks the temp is. C3 suffers with water getting into the ecu plugs, and this can play havoc with actual readings.

[Patt]

Thanks for that. I did check the sensor plug/socket and it looked clean inside. I've no diagnostic facilities so I'm checking the easy things first. I was surprised to find the sensor did not go into a water passage, it looked like new, so not just gunged up.

[Patt]

Hi all, just an update on this. The ecu light came on so it was time to spend money.
The diagnosis was that two fuel injectors were faulty. Maybe they stuck shut overnight and freed once the engine started.
Thanks for looking.