In late 1984 and early 1985, car owners in the Denver, Colorado area began complaining about driveability. All affected cars had port fuel injection systems. With time, complaints with certain makes of engines spread to other geographical areas. A test method was needed to study the factors causing flow- restricting deposits in the injectors. The Coordinating Research Council Automotive Fuel Injector Deposit Group was organized in March 1986. Within that group, a Test Procedures Subgroup was assigned the task of selecting a vehicle test procedure that related to field experience. Excellent cooperation between the automotive, petroleum, and supplier industries helped identify a test method that duplicated field experience involving injector deposits. This paper describes the CRC program to explore repeatability and reproducibility of the method.