Truck hesitation

[drillingmachine]

my 89 burb seems to hesitate more now that i put Lucas complete tune up in my gas tank. I have had the plug wires changed, plugs gaped and replaced, fuel filter replaced, rotor cap replaced. It hesitates more when I first use it that day. when it does hesitate I floor it so it can get past it and does pretty well. sometimes i can hear it make a pop sound in under the hood, when this happens. I don't know if this has anything to do with this, but I am down to my last 1/8 tank of gas and has started to hesitate even more. Oh, one more thing, sometimes when at a stop or idle, the idle goes "up and down". I do have a bad battery that I need to change.

Is there a way that the fuel pump can get clogged? could it be bad gas? I have cycled through gas several times over. could it be some kind of spark problem?
I didn't post this in suburbans forum because people hardly look at that forum.