The 88 4 cylinder should have FI.
There was a similar thread to this recently, first questions is when was the fuel filter last replaced, and when you replaced the pump did you put a new sock on the pump?
If both of those are in a known good condition, the next step is to throw a fuel pressure gauge on the fuel port and see what your fuel pressure looks like at idle, and various RPM ranges. Report back with that info and we can point you in the right direction from there. With multiple Napa pumps being swapped in, my inclination would be to think that you are not getting a full 12v to the pump, you can also take the vac. hose off of the fuel pressure regulator and make sure it doesn't smell like gas, a leaking regulator could cause some of the issues you have noted.
With regard to the pump noise....I wouldn't worry too much, you are practically sitting on top of the gas tank, and the pump is hard mounted to the tank, so the noise of the pump running is really easily transmitted through the floor behind you and into your ear...let the fuel pressure gauge tell you what the health of the pump is, not your ear...that test only works in cars where a trunk filled with carpet is used to buffer the noise of the pump.