i have a 90 civic hatch. it doesnt start at all. alternator is good. starter is good. what other possible problems could there be?

 

is it turning over...if so, then the problem is fuel or spark

if not, then at minimum, the problem is starter/ign switch

if you are turning over, then next check spark by using either electronic spark detector or holding the plug electrode close to a chassis ground and looking for spark while cranking. Is spark is good, then check fuel pressure.