I have a 85 Ford LTD 3.8 fuel injected. The other day it started hesitating while driving around 50 mph. In a 20 mile strech it went from hesitating or jumping/jerking once a minute to hesitating constatntly. Under heavy acceleration it will stop, and then return when I let off the gas. I added some injector cleaner and the problem went away for about 4-5 days. When it started hesitating again, i replaced the fuel filter. It went away again but only for part of a day. I have added more injector cleaner and it has stopped again, but I just know it will return. I can hear the fuel pump kick on when i start the car, no change from when I bouht the car 2 years ago. Any ideas?