help!! 92 accord start up problems

have had trouble starting my accord. had the fuel pump, fuel filter changed. and its still doing the same thing. car cranks but doesn't turn over. 10 minutes later it will start. checked the fuel pressure and sometimes it registers a normal reading and other times it registers nothing. what can anyone suggest i do next?? mechanic says i should change the PGM-FI main relay, does this sound right? please advise. thanks

Make sure there is spark, if so I would replace the main relay.