my 89 cherokee hesitates to shift in to an upper gear. It doesn't shift up until the rpm are up into the 5-6 thousnds. I was messing with the vaccum lines and the idol whenn it started. Does Any one have any ideas?

my 89 cherokee hesitates to shift in to an upper gear. It doesn't shift up until the rpm are up into the 5-6 thousnds. I was messing with the vaccum lines and the idol whenn it started. Does Any one have any ideas?

Of course, re-check your vacuum lines, but you will also need to check your TPS (throttle position sensor). It tells the tranny when to shift.