Hey guys I have a 91' f-150. with dual gas tanks, The front tank when I put gas in it makes the truck hesitant, jerky and slugish as if there maybe water in the tank. I have sifined and pulled the tank out to make sure there is no water in it. still have the same problem. any ideas?

 

i'm willing to bet its the low pressure pump in your tank. You should have a low pressure pump in the tank and a high pressure one on the frame rail. The low pressure will deliver fuel to the high pressure. I imagine you could have problems if the low pressure pump is not around

 

1990 and up have high pressure pump in tank.

 

well so much for that idea then! Did they also use different selector valves between the 2 tanks?

 

No the switch is on the dash I have not changed the unit it self. Sometimes when I add heat to the tank it helps for a while maybe a day if lucky. It only gives problems on take off when I am moving its fine but from a stop sign or red light at take off. Someone also suggested that the cap might not be venting right so the next time I put gas in that tank I am going to leave the cap off and see what happens

 

More likely than not, your in tank fuel pump is not putting out enough pressure. Time for a new one.

 

Fuel pumps is a big ford problem.
If the filter is good, and the other tank works fine, switch out that pump. Its such an easy job.