It will run just fine without a TPS , but your losing a lot of power and gas mileage. I just found that mine is bad on my '89. I tried adjusting it and it didn't help so I unplugged it (just to see what it would do). It didn't change anything , it ran exactly like it does with it plugged in. But , like I said mine is bad. Better get your wallet out , a new one from autozone was $110 !!! I haven't put mine on yet but I know it will make a lot of difference. I have had tps trouble with other trucks and it makes a huge difference if it's working right.
So, to answer your question, YES you need to get a TPS. But, it WILL run without one , it just won't perform as good. Also make sure you adjust it right or it won't help much.
