1997 Jeep Wrangler runs wide open

I have a 1997 jeep wrangler.2.5L While driving 55-60mph on the highway, it sudden accelerated uncontrollably. I got it shut down, pulled over and had it towed home. Throttle linkage is fine, return spring OK. It set no trouble codes, did not show a check engine light, any other indication of a problem. If you attempt to start it, it immediately runs wide open. I changed the TPS, no change. I changed the MAP sensor, no change. I inspected the IAC, and cleaned it, no change. The only indicator I see with a scanner, is the MAP reads 9.4"hg with the engine not running, but it reads the same with the new sensor. Not being much of a mechanic, this looks wrong to me, but not sure why it would read that way. Wiring problem, possibly? What am I missing?