1996 ford E350 evaporative Emission Valve
 

Hi all,
today i finally got around to replacing my fuel pump in the tank,
took off the wiring, straps and started to take off the lines, but i noticed one line was already off and completely caked full of mud, indication that it's been off for a long time, it's the front line on the rear valve, seems like it should be capped, and it was completely open at the tank side, what do you guys think will change once i fix that? I'm assuming tank didn't pressurize up till now, does that have anything to do with the vacuum lines that are very essential to keep the vehicle running?

Were you able to find the vacuum diagram under the hood, It should show where those lines go.

i know where they go, i'm just wondering how that hose off can effect the vehicle,
also found these hoses cracked, most likely the reason my pump failed,

When you changed the pump what did the inside of the tank look like? If it had any kind of anything in it, it can plug the pick-up sock and starve the pump and vehicle.
If you know where the hose is supposed to go, according to the diagram , let us know and we should be able to better answer your concerns.

Got it together, had to buy new tank straps, new gas filler tube, fuel pump and gasket for tank, the spin but no start issue is fixed, the sock was dirty on the pump, maybe the pump was still good, but i decided to replace it anyways since it's still original pump..
van has more power, but now something belt driven might need fixed, when i start it it's making bad bearing noise, almost sounded like the air conditioner, will have to check into that now, thanks hanky for the help! without you this forum would be dead, :)

Don't cap it! you experience vapour lock, as I did on my E250 1966 van. It seems to be a vent. I think a check valve open at atmospheric pressure close with very low vacum. I purchased a valve from a motorcycle application but you need to mount it as hight or higer then the tank. a bit of a problem in my van. I hope I helped a bit.BilldarrAz in Tucson.