Quote Originally Posted by jeffimperial View Post
Hi Tsikoters!

I have a 2012 Hyundai Accent (gas) whose engine hesitates or judders every time I engage something electrical like the power windows, aircon, headlights, wipers or sometimes even just the radio.

The juddering is quite subtle; there is very little vibration in the cabin. Just enough to be felt through the steering wheel and annoy me.

I have tried replacing the battery. It was still from the factory anyway. But that did not get rid of the juddering.

I think I want to try fuel system cleaners next (sea foam treatment spray via air intake). But if anyone has any suggestions, it would be highly appeciated!
my wild guess is,
your problem is electrical-related, and not engine-related.
it appears that the current going to your engine is diminished when an electrical appliance is opened.
this suggests to me, of a poor electrical contact, that limits the flow of electricity. it is un-able to conduct larger amounts of electricity.
good luck.