TrimDrip

it is old enough that the wiring could be causing issues with grounds, your computer could have capacitors ready to go, your 02 sensor's heaters may be taking several minutes to get warm. and even after you check all that, you may find out that the cheap air-tex fuel pump is really the problem after all.

88_mustang_5.0

My 88 starts no problem but stalls out shortly after unless I unplug the tps been checking connections and still no luck

TrimDrip

If you are setting the tps, the car doesn't need to be running to do so. I haven't looked at the ford speed density algorithms but, I imagine the throttle position would be apart of it.

It does seem odd that it stalls out though. a mass-air car wouldn't die out