1986 camaro 383 stroker tpi 10.5x1 alum heads 700r4

the problem i'm having is that iam unable to keep an adjustment on my throtle position sensor. i've gone through three in less than 500 miles. car runs fine most of the time, but at any given moment it will die out , upon trying to restart it acts like it's hitting on a couple cylinders, after a couple trys and dying outit hits and runs fine again for the next day,week, month, there is no pattern to the gostly problem.once this starts it's only a matter of time until the idle gets rough/ unsteady, and as it progresses over the next few episodesto where itwill barely run at all. i can send it to my mechanic buddy he puts a new t.p.s in it adjusts it and we're fine again. my car has a custom prom chip, and about a year ago i had to replace the comp, any ideas guys?