I reattached the lines to the canister, filled up the gas tank, and put the cap on tight. The VSV is there and attached properly, as far as I know. We'll see if the problem persists. I will say, it's been about 50 miles since I put the lines back on, and when it's up to temp it feels a little more... peppy? Is that a technical term? I used to think it got sluggish after it warmed up because that was the nature of the car. Now I'm starting to think it might have been starving the fuel pump when it used enough gas to create a vacuum.

Could the extra stress put on the pump from fighting a pressure gradient cause early failure? Maybe this explains why the pump was replaced by the PO? He took it to a dealership, though. I would like to think they would have noticed the oddball vacuum lines.

I'm going to drive it until I either run out of gas or it starts sputtering again. Thanks for the help!

 

won't kill the pump that fast, it will have to happen for a while but it is possible for it to go out.
it should feel more peppy though the fuel mixture was probably off.
just keep an eye on things and maybe check over the other hoses in the engine bay.
if you see more open vac nipples like that on something else you know its hooked up wrong.