If I recall, 91 went to a different injection system and thus the pcm is different, this could be part of your problem as the pcm sets the timing etc.
2013 WRANGLER SPORT 2 DR., V-6 ,AUTO,HARD TOP
)1994 Jeep Wrangler 2.5L, Bestop top
/w steel half door and slider windows
5 speed, 2.5" lift, 31" tires,rack lights