My problem is my carb. is cutting out at highway speeds and also underloads(up hills). It seems as if the 40 has a rev. limiter........ I believe it isn't getting enough fuel. The background is; I have a 1977 fj40, it has a freshly rebuilt engine, stock intake and exhaust, and I am running a non-usa distributor., and I have an electric fuel pump that I purchased for the weber carb. from TPI4x4. that I was running up until now. I was until recently running a weber carb. and with this set-up I had no such similiar problems. Then I decided to go back stock on the carb. as well. So I had a 76 2bbl. asain rebuilt for me. I have the carb. dialed in and running smooth at idle, it runs great until the afore mentioned cutting out at high end. The only thing I can think that might be the problem is the eletric fuel pump might not be flowing enough gas at high rpms and wide open throttle. I still have my stock fuel pump and am considering reinstalling it to see if that will solve the issue, but before I yank the eletric pump out I wanted to hear from you guys.