1987 TBI wontstay running, i did tune up and fuel filter already !!

[Rumble]

my truck is actually an 89 crew , so its square body, it ran decent when i bought it, not great, i finally got around to doing a tune up and still ran crappy, just did fuel filter, still wont stay running, it will start.

If i tap the gas constantly it will run rough, but no pedal and and steady pedal and it will die

I noticed a greeen wire on the passenger side of block near exhaust manifold, the tip was broken and dry rotted, looks like it connects to a sensor there, any idea what it is???????

thanx