Hello!

So, we just replaced the fuel pump a couple of weeks ago (it had died
on us). Last night the car would turn over but not start but after
walking away and coming back it started again. This morning it started
with no problem but this afternoon it's gone back to the "I'm not going
to start but I'm going to turn over. So nyeh." What should we do? My
boyfriend says he doesn't think it's the spark plugs. I'm a bit
clueless when it comes to cars, so any help would be appreciated.
Thanks muchly!