Throttle Coking Measurement Development and Thickness Variation Analysis of Field Return Throttles

This analysis was undertaken to improve the understanding of the throttle and fuel types, exhaust gas recirculation, and mileage that affect the thickness and location of throttle deposit formation.

Some automotive internal combustion engine throttle bodies have experienced field issues causing increased torque in the opening direction or idle stability/stalls. To increase the understanding of the factors affecting throttle deposit formation, a measurement system was developed to quantify throttle deposit thickness. Furthermore, an analysis of variance was completed on throttles from known field usage to identify factors such as oil type, fuel type, EGR, throttle type that affect deposit thickness.

Through an analysis of field vehicles with known history and throttle deposits this initial analysis identifies the key factors affecting throttle deposit build up.