Hey all I have a 91 s15 Jimmy w/ 4.3 & TBI. On the interstate at 80mph in low grade hills the mph drops off of 80. Tranny unlocks and raises rpm's. Is it too old being made when the speed limit was 55. Gave it tune up with no help. Thinking about a hypertech chip or K&N filter to try to help it get down the road. Any suggestions would be helpful. Thank
- posted
20 years ago