I was just given a 1985 F250 with a 302 fuel injected engine. It has been running rough and I have thus far found the fuel pressure regulator was bad. That improved the situation about 90%. However, I need a question answered. Were some of the 1985 fuel injected engines produced with just one external fuel pump? This truck has dual tanks and I dropped the front tank but there was no internal pump. There was a gap in the sending unit that looked as if a pump should be there but I have been told that some of the first production units only came with the external pump. The thing acts like it is sucking air or can't keep the high pressure pump primed. I now think someone either cut that boost pump out. So should I change the sending unit out to one with a internal tank pump?