i have a non racecar related issue that i need some help with. i have a 92 geo tracker that runs great at an idle or if you bring the throttle up slowly. but when i floor it the engine bogs down and the rpm wont pick up. but if i restrict the fuel return line the engine will run normally. i have al...

I've heard that there are certain types of cars that have speedo valves and there are also others without. What could be the advantage and disadvantage of having that part? sorry coz I don't know if I posted on the right Category.