[LakeCleElum]

I just solved this same problem with my '73.5 this morning.

Even though you have new injectors, my guess is that something has worked it's way thur the system and is partially blocking the fuel from being atomized. You're probably still getting fuel thru, it's just a bad pattern and doesn't burn well below 3,000 RPM (my exact problem). I isolated the cylinder by seeing which plug was darker than the others. (Remember, it's getting fuel, it just doesn't burn at low speeds).

My bad injector was #5. I compared the spray pattern between #4 and #5 and immediately saw #5 was bad. Although I plan to have my injectors professionally cleaned this winter, I was able to clean this one myself and my problem has cleared up.

This occurred even though I have recently replaced the fuel filter. I plan to drain and clean my tank this winter. You may consider this also if the car has sit a lot....G'luck...