Sounds like you might just need a tune up. With modern cars that means plugs, wires, distributor cap (if applicable), and distributor rotor (if applicable). Also your air cleaner. Very important on a heavy breather like a TR. The resistance in your wires, cap, and rotor(s) can degrade over time and with use. I would recommend changing these items on a yearly basis if the car is a daily driver and probably every 12,000 miles if it isnít. Basically every fourth oil change.
It sounds like youíre having problems making power under load. First step is to make sure your car is in good operating order. That means a tune up. Then if that doesnít clear it up weíll have you take a look at the a) Oxygen (O2) sensor and b) fuel injectors. Iím guessing youíre not producing enough spark. How did the plugs you pulled look? Were they black or kind of brownish grey? Were all the plugs the same? If not which ones were different? Was one bank of cylinders different than the others?