I have a 1985 F350 ,6.9L deisel that runs rough at ideal. It runs good when you accelerate. Could anyone please help.thank you.

it could be a cloged injector try running some fuel injector treatment mine did the same thing the shop told me i needed a new injector pump for 1000 dollars i ran injector cleaner through 2 tanks of fuel and problem went awaythat was over a year ago

Try new glow plugs and wires, also your fuel filter and air filter. if that doesn't fix it i would do a distributor, and if that ain't it i would do a coil. If it still ain't running right drive it over a cliff and get some insurence money for it!
Well good luck man!!!!!

I'm thinking the same thing as delbe101.
It was my first thought

I have the same year,Check for a crimped fuel line.Check all fuel line connections.Make shure no air is getting in the fuel lines.When you cold start it do you let the motor kick down before you drive it?I have the 420 6.9 IH,and the only problems i have had were bad fuel line,bad injectors,bad glow plugs and a bad ground in the last 15 years.