Alfa Romeo Repair: car cranks but wont start, residual pressure, check valve

Question
I have a 92 Spider it cranks but won't start at times.  Sometimes it starts immediately at other times I have to keep cranking and recranking to get it started.  It eventually starts but it is annoying. Can you please help.  I enjoy my car and don't want to get rid of it.
Thanks

Answer
I would check the fuel pump first. One person listens near the pump while the other turns on the ignition.  The pump should run for 2 seconds.  If it is a hot start problem then the residual pressure of the fuel system needs to be checked. The check valve in the fuel pump should gradually lose pressure over no less than 1/2 hour.

If the pump proves good then it is probalby the ignition module. Check for spark at the spark plug.