Re: 1998 Ranger has a bug.
I had a Mazda-built B2xxx truck that bucked every once once in a while, usually on the highway. Felt like the ignition was cut out completely for about 1/8th second. Replaced various bits over the years and never found it.
2003 Ranger: 2.3L, 5spd, 2wd. Ex-fleet white standard cab truck, stock. 200k+.
AddOns: UltraGauge, AVS vents, $25 craigslist topper, camping/cargo deck.