I have an 88 s 10 4x4 with the 4.3 that i've had since new. For the last few years I've had an intermittent stalling/sputter issue. After driving the truck for a few miles, it will begin to sputter and want to stall when i slow up for a stoplight. I can idle it up and pet it for a few min and then it will be ok. Additionally if I don't have to slow down to a stop it never happens. No idiot lights come on and I'm guessing maybe a sensor or something maybe when it reaches operating temp? By the way, truck has 113000 mi and had new plugs, wires etc put on a yr or so ago and that had no effect on this problem.
thanks

I would try cleaning TBI body and IAC valve.
Check egr valve for sticking open.
And check for codes.