Kia Rio Engine Problems

It's clearly a happy camper when it's cold and it's getting the cold settings, it's clearly not when the cold settings are not in play. It could be a problem with the ECU, the crank angle sensor, the oxygen sensor, or the idle setting. You really need to go to a mechanic who can diagnose the problem for you.

I doubt it's the petrol, and like you reckon it could be a sensor. It would be worth cleaning the throttle body as that can sometimes cause the sort of problem you have.

Check the battery, it might not have enough grunt to crank the engine and start it. Batteries are under enormous pressure at this time of the year and if they’re a bit down it will show up.

Check the battery, it might not have enough grunt to crank the engine and start it. Batteries are under enormous pressure at this time of the year and if they’re a bit down it will show up.

I favour following the maker's recommendation when it comes to maintenance. It might seem unnecessary expense when nothing wrong's, but better safe than sorry.

FIRST to your last question. You will wonder why you haven't had fuel-injection before, it is so much better in all respects than a carburettor that you will love it. Your car will start without drama at all temperatures, will drive smoothly at all times, won't suffer from fuel vapourisation, will deliver better fuel economy and have more power. As for the Accent and Rio, I can't give you a definitive answer other than the Accent has a good reputation within the trade. The Rio isn't quite as well regarded. The feeling is that Kia is about where Hyundai was five years ago in build quality and reliability. I would favour the Hyundai, but don't have any major Kia objection.