The CRC Port Fuel Injector Bench Test Method, Interlaboratory Study, and Vehicle Test Correlation

Port-fuel-injection (PFI) problems were first reported late in 1984. Deposits that formed on the tip of the pintle-type injectors of certain engines restricted fuel flow and caused driveability and emission problems. Responding to this problem, industry test programs were initiated to reproduce the deposits under controlled conditions. In 1986, a vehicle test procedure was identified and the automotive industry recommended a pass/fail performance level. Building upon available information, the Coordinating Research Council's (CRC) Port Fuel Injector Deposit Group developed a standard vehicle test procedure to evaluate various unleaded gasolines for port-fuel-injection fouling. The vehicle test procedure was adopted as an ASTM test method. The United States Environmental Protection Agency (EPA) and the State of California accepted the procedure as the standard for measuring a gasoline's propensity to form deposits in a pintle-type injector. Since there is interest in maintaining a performance-based PFI test, the CRC Group has been working to gain support for an industry standard bench test method as an alternative for verifying minimum cleanliness performance of commercial gasolines.

Data have been generated comparing the fuel-injector-fouling tendency of the bench test versus fouling in vehicle tests. The results are presented in this paper to show the correlation between the tests. An interlaboratory study has also been conducted to determine the bench test method repeatability and reproducibility.