2000 import tech roundup

Motor, Dec 1999 by Weissler, Paul

The S2000's engine is relatively small at just 2 liters, but with Honda's VTEC system (variable valve timing and lift) working, produces an astounding 240 hp-NN4thout a turbo or supercharger. Of course, the secret is high revving-the redline area starts at 9000 rpm. The new 2-liter has a timing chain, not the familiar Honda belt, and the intake and exhaust cam sprockets mesh with a Toyota-like scissors gear. A giant air cleaner allows the engine to really inhale at high rpm.

To help meet Califomia's LEV emissions standards, the engine has a cornputer-controlled electric air pump that feeds air to the exhaust ports during a cold start, for quick catalyst lightoff. The pump (behind the left headlamp) has a current sensor (on the left fender well) wired to it and to the engine computer, to monitor pump operation and signal any-indication that it's not doing the job.

Lots of Honda diagnostic routines have "substitute with known-good engine computer" as a troubleshooting step. You probably won't have one (in your shelf, but Honda has shaped its ignition keys so you can use the same model car as a temporary donor. just tape the donors key head to a new key made by cutting an ordinary key to the shape of the one in the sick car. This way, the donor key head will provide the antitheft coding needed for the donor computer to work. This technique, introduced in 1996-97, has gone across the Honda line to the S2000.

Electric-assist power steering has long been put on the back burner by most vehicle manufacturers because of the need for high-capacity-and therefore expensive--electronics. The S2000 gets the feature using moderate-capacity electronics thanks to the chassis/powertrain layout. Honda puts much of the north-south powertrain to the rear, taking some of the weight off the front wheels, where the electric motor resides. The motor is a reversible 12-volt DC type, and the armature has a recirculating ball setup for low friction. The system's electronic torque sensor is wired to a separate computer next to the battery and measures road resistance and steering wheel position.

The electric-assist computer has self-diagnostic functions. You can pull DTCs out of the OBD 11 connector (under the dash on the passenger's side) by grounding the connector's electric steering diagnostic output terminal. By the way, if you ever have to replace the torque sensor or remove it for a steering gear replacement, you'll have to "teach" the electronic module the position of the sensor, which during installation can be located with alignment marks. Keep these requirements in mind and refer to your service information system for specifics when the occasion arises. Of course, don't forget the basics if the power fails: The 70-amp fuse that protects the circuit should be at the top of your checklist.

Because the torque-sensing rear diff is a limited-shp design, Honda warns there could be premature wear if the car suffers a flat rear tire and the compact spare is used. You've got to take off a front wheel, remount it at the rear and use the compact in front.