Not exactly sure. Was driving when the revs started jumping (one sec i was at 3rpm moving the next sec the car stops and the revs dropped instantly to 1rpm then back to normal. After this the car shuts down. I went and check the fuse box and the snsr fuse blew, so i changed and blew it againg. I added more tape to the connection where the wire from the icebox connects to the yellow one on the fusebox and changed againg the fuse and it worked. Drove the car the entire day with no more problem, except when i turned the a/c on the car started to vibrate very hard. The next day i didnt touch the car until today that when i was going to use it the var didnt started.
This just happened to my car. I let my friend use it while I'm out here in the Mojave and he reported the same thing (is this a massive Hyundai resistance coming on?).
He had one of his mechanic buddies come over to look at it. Fuel pump is priming, but the plugs aren't getting any spark. I suggested to him to clean the battery terminals, check the ground wires on the alternator and firewall, and have the battery tested.
If it's not those things you may have a short in your wires or need a new starter coil. I bought new plugs and wires a couple months ago...just need to find the time to get them in =/. Hope this helps.