Hi Everyone im new here and need some help please..
I have a 98 jeep grand cherokee, have a 3.5inch lift and 15x10 with 33. I have changed spark plugs, wires, cleaned throttle, IAC. The problem is when im driving and im going between 60mph to 75mph maybe around 2000rpm, rpm needle starts to jump or when i go over a bumo and it feel heavy. If i go slower than 60mph don't have any problems. Any help please...