Determination of Engine Cold Start Fuel Requirements Using A Programmable Electronic Choke

The programmable choke is a development tool designed to obtain detailed, precise knowledge of choke rich and lean limits during cold start and driveaway tests. It is a servomechanism that replaces the bimetal spring in a conventional choke, and controls and measures choke plate angle to within one percent. Detailed knowledge of choke calibration requirements, over the ambient temperature range is used to improve bimetal choke designs. This report describes the programmable choke and presents results of tests conducted on 460 CID vehicles equipped with this system.