So I bought another cherokee this weekend, an 89, and it works good but will not shift out of first gear and drops to an iddle when you let off the throttle going down the road and then jumps back up to RPM when you hit it again, kinda like a th350 with the vacuum line off. Thoughts? He did say he washed the engine compartment before it started, did he knock something off or loose and what or where would it be?