90 Honda Prelude running rich!!! help!?

There are a couple of common causes of this problem and a million reasons! Lol The first thing that I would check is the vacuum line to the MAP (manifold absolute pressure) sensor for being cracked, torn or not connected. Next, an out-of-range CTS (coolant temperature sensor) will cause a rich mixture also a ruptured diaphragm of the fuel pressure regulator will too. Also the system goes into open loop (no O2 sensor calculations) When the throttle opening reaches 80% it has nothing to do with the RPM!