Misfiring Engine Hyundai Accent Executive

Question

My Hyundai Accent Executive is 2001 model. Recently the engine started misfiring badly during idling with Air conditioner on. It is almost like the engine is going to turn off any moment. The condition is little better when AC is off. Few days ago, AC went offline and the misfire vanished, though it could be noticed every now and then. There was a fuse problem which cut off the power supply to AC clutch. The fuse was replaced and the problem came back. I could see that there is electrical problem but we could not pinpoint the problem area. The spark plugs are new, the injectors are cleaned and still the problem is persisting.

Answer 1

A heavy misfire is indicated by a blinking Check Engine or Service Engine Soon light.

Few days ago, AC went offline and the misfire vanished

The fact that there was a fuse issue involving the A/C Compressor. I'm going to put my finger on one of the following scenarios:

1. A/C Compressor is binding or damaged internally. I am not going to say it's seized because if that were the case it would not rotate at all, and the belt would burn and break. And you would know it seized. The compressor can easily be checked if you have the tools and capability to remove the A/C belt yourself and spin the compressor by hand.

2. There is something other than R-134a in the A/C system that the compressor is having a difficult time with. I've seen a lot of absolutely mind-boggling fluids/gasses pumped into an A/C system. I would have the system professionally evacuated and you should also make sure that when they vacuum the system that they perform it for full time. A lot of shops tend to "fast forward" through the process leaving moisture in the system. If you go to a shop that you've never been to before, then it might be a good idea to stick around during the process. You might even learn a thing or two.

The matter of the A/C Compressor blowing a fuse would happen with either of these scenarios. The compressor would demand more power in order to perform and end up overloading the circuit or causing the compressor to overheat. Either case would blow the fuse.