I have a 99 24 valve that wont start unless you use either,and then it runs just fine, what do i need to do to fix this problem

 

Could be a few problems.

Do you have any codes?
Any fuses blown?
What did or what were you doing up to this point?
Did you run it out of fuel?

A little more info would be good to help you out. That question right there if you went to a shop would mean dollar signs in the mechanics mind.