if it has been getting worse and worse, then i would really look to the fuel pump being the issue.
just a cheap, inline fuel pressure gauge on the incoming fuel line would be enough to tell you if there is a fuel pressure issue, but with 160k on the clock, I would bet that the fuel pump is on its way out.
the walboro is the cheap replacement option. Just remember, there is a difference between cheap and inexpensive, and the walboro is cheap. Some people have lots of luck. Others end up replacing it almost once a year, and others get bad apples right out of the box. I personally have experienced all 3 at various times with various cars.
Don't forget the fuel filters too. i've seen too many people kill brand new fuel pumps because they forgot to change their clogged up fuel filter.
I would start there and see where i'm at once I know for sure that I am getting ample consistent fuel pressure.


As for the "good or not" that is sort of true. It is true that with fuel injection systems, the pressure has to be right, or it won't work. However, there is still a range it will work in, it is just much more narrow than say that of a carburetor set up. Also, even stock, the fuel pressure is typically a bit higher than it absolutely needs to be. This is done to help with the whole longevity issue. Think of it this way. If the requirement is no less than 40psi. And you loose 2% a year, every year. Then what would be smarter? To start off with 42psi, or 48 psi?
The fuel pump is essentially, just an electric motor. As with all electric motors, as they start to go bad, they draw more voltage. The problem with that is, the wires don't get any larger, so the added voltage heats up the wiring more. As heat goes up, resistance goes up. Eventually, it hits the breaking point where the wire builds up so much resistance that it simply cannot pass any more voltage through. This is when the motor starts to slow down. See, as long as it can continue to pull more voltage, it will do a decent job at maintaining the proper speed. But once the voltage reaches its cap, the motor will slow down. In a fuel pump application, this is when fuel pressure starts to drop. Remember that 42psi vs 48 psi example? Say you are at 48 psi and you need at least 40, well, the pump can slow down, and the pressure can drop down quite a bit before there is a noticeable drop in performance. But once it finally drops to 39 psi, the engine will bog down. Now, applying this to your situation, (and also why it makes sense that it is the fuel pump) when the engine bogs down, the load on the fuel pump drops. It doesn't need to pump as much fuel because the engine is slowing down. This allows the voltage to drop back down. Remember, more voltage = more heat. Therefore, the drop in voltage allows a drop in heat. This allows everything to cool off. Cooling off drops the resistance down, which in turn allows more voltage. The pump can then draw the higher level of voltage again and the engine speeds back up. See how that cycle fits your symptoms?

It is a good fit. Not a guarantee. It could be something totally different and the ECU is just compensating for it by pulling the timing crazy retarded and doing everything it can to keep itself alive until things settle out and then it goes back to normal. but because it is a good fit, it is where I would start.