Hopefully this post will help someone with the same problem I had.

Truck is '98 4x4 with 2.7L, 5-speed
Problem was it would have this hiccup that felt like the engine died for a split second. It would happen every few minutes and usually at very light throttle acceleration. Most often it would happen just as I was letting up on the gas after accelerating from a stop light. After searching here I found a few likely causes: fuel filter, ignitor, spark plugs, throttle position sensor (TPS). Since the TPS is the easiest thing to check that's what I started with. The resistance is supposed to change smoothly with changing throttle position but mine showed a few spikes in resistance. I ordered a new one online for $48 shipped and installed it in 30 minutes. Truck runs perfectly now, been driving it for 4 days and not a single hiccup.

key words: hesitation, stumble, missing