My F-250's Center tank was not working for long time. Three days ago I changed the fuel pump and put a new fuel filter that and fixed the problem.
I had to pump gas out to drop the tank becasue it was full, so I used that gas for the rear. Since I filled the rear tank Im using it first.

First day truck worked just fine.
Second day in the morning the truck studdered at start, but a few minutes later worked fine but with a little smoke if I steped on the gas.

Today the truck has been studdering my whole trip and lots of smoke.

Can that be the old gasoline that was in the center tank? it stinks

the rear tank was not full so I pumped 5 more galons today of new gas but still doing the same.
the rear still had some old gas in the bottom and I also added 10 more gallons but still smoking the same.
Can some one please tell me this is just a bad gas issue? how long will it last?? or did I blow my engine??

 

I'm thinking it is most likely bad gas. Did you try switching to another tank with completely fresh gas in it to see if it kept on doing that?

I would mix up three or four gallons of 50:1 with premium gas and put it in there if you do not want to drain the tank