I'm posting this for a buddy. He's got a good deal on a running 1993 F250, 351/Auto/2wd. The problem is once the engine reaches operating temp it hunts like a starving carb and will die unless someone feathers the gas. It has just recieved: a new radiator, hoses, Coolant temp sensor, water pump. It has dual tanks and doesn't run any different when you switch from one tank to the other. I'm thinking it's the TPS because nothing changes when you unplug it with the engine running. What do you guys think?

 

I would check the IAC valve first. Ford Fuel Injection » Idle Air Bypass (IAB)

 

What he said.......Good starting point.