New EFI and Heat Management System

     Last year Harley Davidson introduced a new Electronic Sequential Port Fuel Injection (ESPFI) system on the 2001 line of Softail motorcycles. The system combined the best features of EFI ideal fuel delivery at all temperatures and altitudes-- with new technology that retains the hearty rumble and "potato - potato" sound of the Harley V-Twin. The same ESPFI system is now offered on 2002 Touring models.
     Several key features differentiate the new ESPFI system from the previous design, the most significant being the use of speed density  ( or intake manifold pressure) as the primary factory in fuel control, rather 
than throttle position.

A new EFI system graces all 2002 Harley Davidson Touring models equipped with EFI. It uses speed density as the primary factor in fuel control and ion-sensing knock detection (via the two terminal sensor illustrated by the drawing) to monitor engine performance. A new three-phase heat management system is also employed to help keep the rider cool.

     By measuring manifold pressure, intake air temperature, engine temperature and throttle position on a per-cylinder, the new Touring EFI system compensates for potential air leaks, calculates real engine load (versus a theoretical load of throttle position only systems) and is more sensitive to fuel control, particularly at lower throttle levels. That's not all.
     A closed loop idle control reads motor RPM to control idle, thereby elimination problems associated with air leaks. Idle on the new Touring models is set at 1000 RPM, however, a H-D dealer can recalibrate idle between 800-1250 RPM. The new system used ion-sensing technology to continuously monitor and adjust performance in accordance with hot weather and fuel quality.  And to reduce the complexity and improve reliability of the new ESPFI, the return fuel line used on the previous EFI system has been eliminated.
     On the road, the benefits of the new ESPFI system are undeniable. The familiar "potato-potato" sound flows from the exhaust as pure as any 45-degree V-Twin from The Motor Company. There are no hesitations or inconsistencies sometimes associated with improperly tuned carburetors. Twist the throttle and the 14500cc motor responds instantly. Fuel economy is generally 2-3 MPG better than carbureted models, although mileage will vary depending upon conditions and riding style, and ESPFI requires no jetting, no hassling with choke and idle controls and smooth starts in all temperature conditions.
     Complementing the new ESPFI induction is an all-new, three-phase heat management system designed to keep riders cooler. Based on engine temperature and the bike's condition (moving or stationary), three different strategies are employed to manage engine heat by automatically varying idle speed and fuel delivery.
     The result is more consistent, cooler engine operation and reduced heat felt by the rider. Heat management is possible only with the new ESPFI-equipped models, and it's yet another hidden technology inside Harley-Davidson Touring models like the Road King Classic.

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Site Last Updated:January 22, 2004   RETURN TO HOME