Could someone please help with this. I have a 2005 Chevy Silverado V6 and anytime the fuel gets to about a 1/4 tank it picks up allot of hesitation and no pick up when accelerating.I have to very slowly add pressure to the gas pedal to even get it to move. After adding gas to 1/2 to 3/4 tank or more it does fine until I use passing gear then the hesitation returns. The truck has 80k on it.

 

Sounds like its time for a fuel filter. Possibly a new strainer. Worst case senerio a new fuel pump. Sounds more like the first two, wouldn't necessarily be fuel pump if it was so intermittent depending on the level of fuel.

 

Fuel filter starvation from:
1.You add pressure to the pedal and increase the fuel pressure in the line, pushing all the debris in the filter against the element blocking the path of fuel. Once you let off, the pressure decreases, causing the debris to "let up" enough for fuel to pass through.
OR
2. The engine is starving for fuel because the fuel pressure is consistanly low. More than likely due to clogged filter. (But its not unheard of to have debris in the tank clogging the strainer. Similar symptoms come from a fuel pump wearing out too.)

If the fuel filter is good and the pressure is up, it could be:
1. EGR (they get stuck open)
2. PCV (same)
3. Or simply a tune up.
4.....there is more.

 

i would go with strainer or fuel filter before you do anything else.