I think, the problem of your relaxation generator neither is a missing "kick" not any other starting aid. It is simply the limited slew rate of the opamp that does not allow operation as desired. The integrator time constant is app. 180nsec only.
Just to test the circuit - try to increase the capacitor by a factor of 1000 and see if it works.
Such a relaxation generator does not need any starting aid at all (assuming real opamp models and finite power supplies) because the integrator will start ramping at t=0.
More than that, these oscillators will not work for ideal opamps (VCVS) because the opamp with pos. feedback must be able to "jump" to a finite voltage. Hence, a real model with fixed supply limits is required.