I must first say as an ASE master tech and educator, that because of the symptoms you described, any answer would be hit or miss. Your vehicle requires analysis with test equipment.
I will try my best to speculate, I clearly repeat speculate, on what the problem might be.
Since you said that the condition becomes less severe as you accelerate, the likelihood of a voltage deficiency in your ignition system is very minimal. This turns us to fuel delivery. The replacement of a fuel pump and filter is acknowledged. Two items which are hard parts for the fuel system were not yet addressed.
The fuel pressure regulator, and the fuel pressure regulator module, a device which controls the regulator itself. In most cases the module would fail before the regulator would. I speculate by greatest likelihood that the fuel pressure regulator module is the problem. When this module fails the regulator itself will still operate satisfactorily. Failure of the module may not necessarily illuminate a check the engine light due to its malfunction if it is still providing the proper signal back to the computer. The symptoms you describe are somewhat similar to the symptoms that a failed module would give. I say this because everyone has their own description of a symptom. A module that has failed would typically give what the technician refers to as a bucking. As you are cruising, the car will buck back and forth giving a sort of on and off sensation. Chugging is a little different whereas there still is power but a smoother and much less amount of it regardless of throttle position.
The vehicle was in 1994 Pontiac and you said a vacuum line was off of a component and you place it back on?
Definitely bring your car into a shop with a certified technician. They will charge you for half an hour and tell you everything that's wrong with your car in the way of running condition.
I am sorry, but I cannot help but suspect that there could be other conditions if you said that a hose was off and you place it back on. Are you positive that you put it back in the correct spot? When the hose was off there was no check engine light? This would make most auto technicians think something is fishy.
If you just go into a local shop and tell them:
Hey look I'm really sorry but all I have is 40 bucks and I just wanna figure out what's wrong with my car. I'm not asking you to fix it for me, I just wanna find out what it is that needs repair, and I'll leave the car here for as long as you need it. Can you please help me out.
If you approach some nice guys in a shop upfront like that, even a shop owner; I know I have a heart, and I do it for sure. Matter of fact in some cases it would make perfect sense to not even take a dime from you. Shops thrive by word of mouth.
I sincerely do hope that you find the problem with your vehicle.
EDIT: by the way one last thing, happy birthday next Monday
