We present a reliable scheme for engineering arbitrary motional ionic states through an adaptation of the projection synthesis technique for trapped ion phenomena. Starting from a prepared coherent motional state, the Wigner function of the desired state is thus sculpted from a Gaussian distribution.The engineering process has also been developed to take into account the errors arising from intensity fluctuations in the exciting laser pulses required for manipulating the electronic and vibrational states of the trapped ion.To this end, a recently developed phenomenological-operator approach that allows for the influence of noise will be applied. This approach furnishes a straightforward technique to estimate the fidelity of the prepared state in the presence of errors, precluding the usual extensive ab initio calculations. The results obtained here by the phenomenological approach, to account for the effects of noise in our engineering scheme, can be directly applied to any other process involving trapped-ion phenomena.