91 dodge stealth idle issue

Have you checked the ICS (idle control servo)? Mine was doing the same thing: would start fine, then after a short bit, it would just stall. The ICS controls air to the throttle body by a moving plunger. I actually took mine out and tested the resistances on it, and that was fine, but noticed what looked like perhaps a small gap where air ‘might’ be getting passed (it was darker in one area of the plastic gasket). Having said all that, the part was pretty cheap and the swap was also pretty easy. Good luck!