2010 Sonata will not start

A few things are possible don't guess! Have it read for codes, even if the check engine light is NOT on the computer will have stored information and codes. Discount auto stores will read codes for no fee. write them down.

Had this problem on our 2010 Sonata and it was intermittent and seemed to only occur on hot or warm days. The car just wouldn't start, it would crank and all the lights and power worked, so it wasn't the battery but it refused to kick in and run. thought we flooded it the first time cause a few hours later it worked again second time it took a bit longer but next day it started and an fine for weeks. third time we took to our mechanic the next day and of course it was working fine then so they suggested we replace the Engine Control Relay (about $110 installed) and we did that and it ran fine for 3 weeks, but it seemed to have a few hard starts and then the next really hot day it did it to us again when we stopped to refuel. it again just cranked but wouldn't start. Got it in to Hyundai dealer that time, while it was still not starting, and they traced it to the fuel pump. they said that the pump refused to engage for them even when they wired power directly to it so they knew something when on it. Cost us $550 for the pump replacement plus $150 to clean the fuel injection system (Not sure we needed the later for the fuel injection cleaning but I gave in so $700 total) anyhow it does seems to be working fine now so hopefully they were right. I blogged engine cranking but not starting and found references to that being either a bad fuel pump or a broken timing belt or timing chain ( i think they were right cause its working now and a broken belt or chain would probably not be an intermittent thing). well that's my story I'll blog back if it dies again.