Why does my Esprit engine rev so high when I cold start it?
Many people panic the first time they start certain 4-cylinder Esprits with the engine cold. Usually (but not always ) the RPMs climb rapidly to 2,500 or higher. Relax. This is normal behavior. In order to meet federal emissions regulations, the Esprit engine management system contains two components called the Exhaust Back Pressure Valve (EBPV) and the Throttle Jacking Capsule. The purpose of these two items is to bring the catalytic converter up to operating temperature as quickly as possible. This is done because converters don’t work well at removing pollutants from exhaust gasses until they are warmed up. In the simplest terms, this is what occurs: When the engine is being cold-started, the engine management computer (ECM) sends a command that closes the EBPV. This valve is located within the exhaust pipe, at the union between the rear of the catalytic converter and the pipe going to the muffler (silencer). Closing this valve essentially blocks the exhaust, trapping heat which cau
