2003 hyundai turns over but does not start

Do you have access to an OBD II diagnostic tool that reads data? I'm interested as to what the TPS, and coolant sensors are reading when the car DOESN'T start.

Check all battery and ground connections and clean them.You may have a bad relay or starter also.

check the injectors with a noid light you may find a bad one. if not check the compression.

sounds like a bent wheel (rim) have you reciently hit any potholes or curbs

Have a qualified Hyundai Service Technician properly diagnose your vehicle

Turn key on and see if you can hear the fuel pump running.

idk

dear friend-did somebody not fit a double contact globe in a single contact holder.also check and clean the earth points.

we had a hyundai once, that stopped and started for no apparent reason , after much looking at and mechanics it turned out to be some butterfly or non return valves leading from the fuel pump to the engine. they were closing up and stopping fuel from passing through , might be the same kind of thing . hope this helps

Check if fuel pump fuse is blown, and fuel filter to be clean or replace it.