Will not start

Thanks Roy, I tested the fuel pressure and it's OK. Goes to 44 and then drops to 30 after 15 minutes. What should I check next? Thanks.

Got some new info today. It wouldn't start while in my driveway so I had it towed to a shop to replace the fuel pump because I couldn't drop the tank at home. It started fine at the shop and the fuel pressure measured at 49-52. He determined it has a exhaust leak at the manifold pipe connection and he says that makes it run rich and is causing the backfiring and bogging down. He was afraid to do the exhaust job because he says the bolts will break off and he didn't want to deal with it. It made me think that maybe it wouldn't start because it was on a slight incline in my driveway but he didn't have anything to say about that. I took it home an backed into the driveway and it started fine. I then took it to a bigger shop and parked it on a slight incline nose first. When they went to move it around back it wouldn't start again. I told them to let it roll to flat and it started. They are going to fix the exhaust leak but I'd like to try to fix whatever is making it not start while the nose is elevated. Do you have any thoughts on this? Thanks.

FYI It was the ignition coil.