I am currently doing a confirmatory factor analysis using AMOS. I have 229 cases, no missing data, with a standardized questionnaire of 20 items, 4 factors. However, some indices specify that it does not fit well: C M I N= 343.322, d f=64; G F I=.874; C F I=.817; R M S E A= 0.69.

What should I do? Maybe add the number of my respondents? try out another model?