In this paper, our multi-level theory of time-delay four wave mixing with incoherent light (TDFWM-IL) developed previously for the case of homogeneous broadening system has been extended to a generally inhomogeneous broadening case. From the present theory, a general expression of signal intensity for absorption band with both homogeneous and inhomogeneous broadening is given as a function of mutual time delay τ between two pump beams. Photon echo with incoherent light under the condition of extremely inhomogeneous broadening is discussed, and the difference of results obtained scperately from multi-level and two-level theory is pointed out. It has been demonstrated that the experiment of TDFWM-IL can also be analysed approximately by using an effective two-level model when a weak effect of inhomogeneous broadening of absorption band exists. Finally, our experimental results of TDFWM-IL obtained at zero-phonon line of ruby and absorption edge of cresyl violet film in PMMA are also presented and compared with the theory mentioned above.