I keep coming back to "no fuel". The clue is that you get no black smoke when you floor her. Even the best of them smoke if they are in tune. I would think that you must be starving to get zero smoke. I installed filters at my tank before the electric aux pump.
If you have bad fuel you might be plugging the filter as soon as you install it.
If your fuel is contaminated with gasoline, just a little, I think it runs poorly. A friend got a load of gas and he barely limped home with a powerless engine. Easy test....take of the fuel filler cap and give it a sniff. It should not even remind you of gas. Lots of gas and it won't run. Might be the attendant or the service station tank?
To eliminate anything from the filters back one guy rigged a can of D fuel up to the input of the filters and took the bus for a test ride. He found that the performance was exceptional and then knew where to look for the problem. I think he found that the tank outlet was plugged at the fitting. Always acted like a plugged filter.
Good luck with this. I know how deeply frustrating this must be when you have run out of things to check. If it was running well in the recent past I think that would eliminate the rack as the cause. Me thinks they go down hill gracefully for the most part.