87 5KTQ long crankin time question

["Southerlin, Russ S" <STHRRSAB@edex.litc.lockheed.com>]

My 87 5KTQ is hard to start in the mornings when cold and after a hot
soak of about 30 min. or lolnger.  It just takes excessively long
cranking time to get it started.  

This weekend I took all 5 injector out and ran the fuel pump to check
for leaks and one (number 5 cyc) would seep a small amount that was
barely noticable except for a small amout around the center of the
injector nozzle, with no dripping.

Everything else in the fuel system seemed O.K. although one injector
did have a bad spray pattern at very low pressure.  The air flow
sensor diaphram (not sure if that is the official name for it) moved
smoothly and didn't seem to bind in any way, was centered in the
venturi. All vacuum hoses are intact etc.

When I started the car up this morning it started right away like it
is supposed to but after a 1 hour sit at work it went back to its
long cranking time again.

Could this one seeping (leaking with no drip) injector cause this?

What else could I check? I understand there is a fuel pump relief
valve? that can let fuel pressure bleed off. How can I check this?
TIA