tbi runs better with temp sensor unplugged...need advice

[bigarmzz]

i need some advice guys, this truck of my dads has my scratchin my head, it has a bad miss after it warms up, so first thing i thought was to change the tank, sending unit and fuel filter, after all its like 25 yrs old...felt like it wasnt getting enough fuel, ya know? like it had a clogged fuel filter, but that didnt help

its a 87 tbi, and it starts up and idles fine, after just a few minutes though it runs like crap and sputters real bad....i thought it was the temp sensor, so i put a new on on, didnt help

so i was curious last eve, took it for a spin a few miles, it was sputtering real bad and missing as usual, i pulled over and unplugged the temp sensor, and it ran fine....????

what the heck would make a tbi run better with the temp sensor completely unhooked??? i'm baffled