This invention relates to an engine fuel injection timing control apparatus for controlling a fuel injection timing by adjusting the position of a timer piston via a solenoid valve. In this apparatus, a frequency signal switching means (44) selectively outputs a first frequency signal (W1) and a second frequency signal (W2) having a frequency lower than the first frequency signal (W1) according to an engine speed (Ne) detected by an engine rotational speed detecting means (49) with reference to preset signal switching engine rotational speeds (N.sub.1, N.sub.2, N.sub.3, N.sub.4, N.sub.5). With a driving frequency based on thus outputted frequency signal, a control means (46) duty-controls a timer controlling solenoid valve (39) according to an engine operation state. Here, the signal switching engine rotational speeds (N.sub.1, N.sub.2, N.sub.3, N.sub.4, N.sub.5) are set to levels which yield first predetermined rotational speed differences (U.sub.1, U.sub.2, U.sub.3, U.sub.4, U.sub.5) from engine rotational speeds where the resonance is generated with respect to a first frequency (f.sub.1) and second predetermined rotational speed differences (L.sub.1, L.sub.2, L.sub.3, L.sub.4, L.sub.5) from engine rotational speeds where the resonance is generated with respect to a second frequency (f.sub.2). Consequently, the fluctuation phenomenon of the timer piston can securely be suppressed in the vicinity of resonance points.