I have a 2004 Elantra GT. It will not start intermittently and on a few rare occasion it suddely dies. There does not seem to be any rhyme or reason for this. I have taken out the start relay and cleaned the prongs and have replaced the cam sensor. Does anyone have anymore ideas I could try?

You need to give us a little bit more... when you say it doesn't start... how doesn't it start? Is there just a click? Does it crank but not actually start?

Check for codes. It could easily be explained by a failing Crankshaft Position Sensor, which is my bet.

I can hear the fuel pump. It does crank but it just doesn't want to fire up. Usually after it sits for awhile it will start up again. It started up yesterday morning at about 6 a.m. went a half of block and died and would not start again. I cleaned off the start relay (because this seemed to help the last time it did this) and put some electrical grease on it; and it still would not start. I went back at about 10 a.m. and it started and drove it several different occasions than throughout the rest of the day. Like I said there seems to be no rhyme or reason for it not starting. It has done it on hot days on cold days. In the morning in the evening. After I have driven awhile and the first time I touch it in the morning.

It was doing it quite frequently about 2 months ago and I cleaned up the start relay and haven't had a problem till yesterday.The fuseboard looks clean with no corrosion. So I am open to any suggestions.