This sounds a bit like what my 89 Suburban was doing, could either rough idle or stall occasionally at idle speed, or stumble off idle at low acceleration speeds. It did throw a code OBD1 and accurately called out the TPS. I tested it with a voltmeter and yep the voltage fell flat just off idle. Probably not your issue though with no code. Good luck!
I thought about the TPS as well. Both can act about the same. If it wasn't zero ° out I wouldn't mind messing with it. May be later I will get the big scanner out and see if it tells me anything more.