6.5 turbo diesel issues

[spencer_41188]

I just recently bought a 93 3500hd. I was told it been setting for 10 years being used as storage seeing it is a box truck it didn't surprise me, just gave me a reason to lowball them lol. I replaced the power steering pump and brake hoses and it ran like a top and stopped too lol ... at least around town but when I get it on the highway it gets a hesitation. I read somewhere it is called fish biting. I've checked everything. the tank looks brand new on the inside as well as the pickup screen, lift pump works 5 to 7 psi at idle and down to 2 at wot. new fuel filter, last chance screen is clean, all new injectors and return lines, replaced pmd as well although it's no longer a pm just a d lol also cleaned all grounds. but the hesitation is still there at 55mph. I unplugged the optical sensor and it runs even better but the idle is high and it stalls on occasion when coming up to traffic lights. I'm starting to think this is not a fueling issue but a sensor or electrical issue causing a fuel issue. just seems to me it's cutting back too much fuel. considering going mechanical but cruise control would cost more lol.

I would appreciate any ideas or a link to get me pointed in the right direction