Hi I have a 2000 Ford Ranger 3.0 V6 Flex fuel. I have replaced the engine, the catalytic converter, spark plugs, wires, fuel filter, air filter, idle air controller, and I STILL have a problem with my truck taking forever to be able to accelerate. It seems to act right until I get up to about 40 miles an hour, and then it takes a long time to get up to 55-60. Getting to 70-75 is almost impossible. I have taken it in to 3 mechanics and no one seems to be able to figure out the cause.