Nissan Repair: Nissan Pathfinder: Starting problem, nissan pathfinder, leaky injector

Question
I have an 1988 Nissan Pathfinder (4WD, V6).

I recently replaced the battery(not sure if this has anything to do
with it), however it now has problems starting when the engine
is warmed up.  The car starts fine when the engine is cold or just
starting for the morning.  

When I turn the key to the 'on' position, there is also a clicking
sound that comes from the main relay.  

My first thought is that it may be a fuel pump but I would think
that would just go out altogther.

Any suggestions would be a big help.


Answer
Does the engine crank when it is hot and it is just difficult to get it to run?  If this is the case I would think a leaky injector is flooding out one or more spark plugs.  If it clicks but does not turn over I would be thinking the relay or starter is on its way out.  These are the two options given the information.