Earlier generation Injection Control Units (ICUs) were designed for the operation with residual fuel. Since 2015, Sulphur cap of 0.1% limit was enforced in Emission Controlled Areas (ECA), which is requiring low viscosity fuel oil in use. As consequence, many marine two-stroke engines have encountered issues due to fuel change e.g. frequent fill up of fuel drain tank or premature wear of fuel injection components in ECA operation.
As Global Sulphur cap is introduced in 2020, the challenge of operation with compliant fuels become predominant. In conjunction with maximum worn internal ICU sealing, large fuel leakage toward the fuel injector can occur. Consequently, the fuel is slowly injected even after regular injection period (uncontrolled injection).
ICUs’ malfunction and fuel leakage from high pressure pipe are the top three known failure causes for RT-flex engine injection when operating with compliant fuels, which counted for up to 70% of unexpected engine stoppages according to received customers’ feedback.