The J=2←1 transitions of methyl iodide in the v3, v6, 2v3, v2, v3+v6, and v5 vibrationally-excited states are observed. In v3+V6, the central component, ν360, of the J=2←1, K=1←1 transition is observed at 14.6 MHz, higher than the ν36+ of the l-type doubling. This is interpreted by the fact that the E state with K=−l=±1 is affected more strongly by the Fermi resonance through k356 than is the A state with K=l=±1. The Fermi resonance through k356 causes the Coriolis coupling between v2 and v5 through ζ25(y) to be transferred to v3+v6. As a result, the l-type doubling constant, q6, is determined to be −5.8 MHz. The Stark effect in the presence of the l-type doubling and nuclear quadrupole splitting is formulated and used in the analysis.