ok...it started when i parked it and returned to find it unable to start. when i put starting fluid in the air intake it would run for as long as it had the starting fluid to run off of. I've replace the sending unit +pump and the fuel pressure regulator. The new pump doesnt pump anything. If i reinstall the original one..it pumps but not with enought pressure. I got a second new fuel pump and it does not pump either. I am at a loss of what to check next please help!