Well I just bought this 90 wrangler over the weekend and I love it! Its got the 6 cylinder and its been getting around 12 mpg since I got it which sounds low. Thats when I noticed the 4wd wouldn't work but my front drive shaft wont turn when its in 2hi. Is this the notorous vac controls screwing up? I didnt think it would have this odd combo of the shaft being locked but it not going into 4wd when put into 4wd. And does that milage sound correct if it were partly stuck in 4wd? Thanks for the help to a NEWB!