My 93 honda prelude normally always starts fine but when I parked on a downward slope it wouldn't start and yes it had gas so I used a jack and lifted the front end and it started right up after trying for like a hour this is the 3rd time in the last few months this happend if it's the fuel pump how can I check I'm sure it's fine tho gets gas fine

 

Do some searching on "main relay" and it might help your issue.

 

It's not the main relay could it be anything else maybe it is a fuel pump because when it's upwards it always starts if I park down hill not always gonna start

 

can your hear your pump priming upon initiating? your sending unit could also be intermitting. Should it be your main relay, your fueling wont even initiate.