My car "was" running like a champ during in town driving. However when I take it out on the freeway for 10-15 miles and run between 65 - 70 mph during that time it starts to hesitate and backfire (both on acceleration and deceleration).
here is what I did so far.
checked wires - ok
checked distributor - ok
put some octane booster in yesterday but have not tried it yet.
changed to electronic ignition about 1 month ago.
Any idea what may be causing this. like I said it was running like a champ (in town driving)
Did this start after the dist. change? What brand dist. did you install? I had similar problem with an MSD, car ran fine cold but once warmed up would backfire and act like it had a 3000 rpm rev. limiter. MSDs website has a good tech. page for problem solving. I ended up sending back my distributor and they sent me a new one.