92 K5 Starting Problem

I have a 1992 K5 Blazer with a 350 engine and an intermittent starting problem.  When starting, the engine cranks but will not fire.  Upon checking the throttlebody, there was no fuel.  Added some fuel to the throttlebody and the engine started and ran fine.  The problem did not reoccur for several days and more than a dozen starts.  Does the fuel relay cause the fuel pump to run in the start position?  Other ideas?
 
Thanks 

I had an 86 S10 that had a similar problem.  It would crank fine, but not start.  If I put gas in the throttle body it would start and run.  If I cranked it for 1 1/2 or 2 min it would start.  It took that long to start cause it wasn't building any oil pressure.  The oil pressure trips the fuel pump or the injectors, so you don't freeze your engine.  See what your oil pressure is at when you crank it.

Check your fuel pump and fuel pump relay...  I just replaced my relay 2 weeks ago for the same symptoms.  Check your fuel pump by having someone hit the fuel tank while you are cranking the engine.  The fuel pump only has power for the first 3 seconds of cranking so it has to be done at the same time.  If it starts immediately, its the fuel pump.  If it doesn't, then check the relay for corrosion or other signs of wear.  ...a relay is hella less expensive than replacing the fuel pump... 

...by the way... I would not recommend continuously cranking the engine... you could overheat the starter...