Hyundai Electrical System:ignition Questions

i have a 2000 elantra. just recently (as its getting cold out) it began ...

i have a 2000 elantra. just recently (as its getting cold out) it began having problems starting. it would run fine, just take five or ten tries to start, then it would start fine for a few days. then 10 to 20 tries to get it started. now it wont start at all. it turns over but i pulled a spark plug wire and stuck a socket extention down in it and tested it against the block. there is no spark. it sometimes turns over slowly but most of the time just normal speed. timing belt is fairly new and has no missing teeth. a jump start does nothing and the battery is good icluding cold crank amps anyway. check engine light is on but has been for years. cant get it to a diagnostic machine now.  i do not know if its getting fuel during start up but it has no fuel delivery issues when running. ive heared coil pack, camshaft position sensor, crankshaft position sensor, relay, even frozen fuel line? someone told me it could be a computer issue and that ignition is controlled by the computer and only after start up the engine begins running off sensor readings?(or something like that). what is the most likeley? could a corroded battery cable not sending enough juice through cause this? or maybe a short in a wire to one of these parts cause the same problem? i have no idea, just know it has to be something that only happens during ignition (start up). thanks

No comments have been provided.

Already replaced clock in my Santa Fe. Now radio will come on by itself (when it is shut off), and sometimes when it is on (regular sound) will blare full blast. Sometimes when starting the vehicle the radio will come on by itself (even when the