Why won't Chevy truck won't go over 50 mph?

Answer 1

It really depends on the truck but in my experience as an auto tech. If everything inside the engine is working properly and there is nothing wrong with the engine the problem could lie in the evacuation of exhaust gases ie the catalytic converter. If this is an older vehicle then it may be partially stopped up. Carburated engines that are out of tune for a while can cause this too. Stopped up cataylsts reduce exhaust flow at higher speeds when the engine needs to breath and can cause sluggish shotty performance yet when not under load will run perfectly fine. Newer engines with fuel injection have computers to control the mixture so this is rarer still but can still happen. This can cause the engine to use fule, move much slower and it even disturbs vacuum in the manifold causing fuel delivery problems with the carburator.