Car starts ok, when getting to temp or hot the idle will start to miss, then sometimes it will pick up and rev to about 3,500rpm. If you blip the throttle it will settle it down again.Also if stop when driving it sometimes starts to missfire and stutter you black smoke out the back then it will pick up again and drive ok for a while. Please can anyone help with some advice. Don,t know if it,s speed idle control sticking or something as the car does/ has not been used for ages?

Thanks for any help offered.

 

thanks for your help guys.