Hi Scotty, your car videos have helped many hours of headaches thank you! However I have a 2002 mx5 that doesn't idle well when cold, it'll swing between 1500 rpm and about 300-500 sometimes cutting out, only happens when it's cold and will stop after about 30 seconds of mucking around with the throttle. What could it be?? I've checked spark plugs and they look fine, new coils, new oil and filters.. I'm stumped. Only other things I can think of are sensors but why would it only happen when cold? Thank you for your help!

try this cleaning video, often fixes it https://www.youtube.com/watch?v=NWCKvU2FmDc

Thanks, I'll give it a go. How bad is overfilling the sump with oil? Lots of different opinions around