plotting data of different x values but same number of data points on the same plot

I have 2 sets of data that I want to plot on the same axis. One set of data runs from -23 to 23 and the other runs from -20 to 20. I've tried to plot them both on the same axis but I'm just seeing the image below.

This is my code:

plot(airGa(:,1),airGa(:,3),'Color',c(10,:))

xlim([-20 20])

hold on

plot(vacuuminitial550mbarGa(:,1),vacuuminitial550mbarGa(:,3),'Color',c(20,:))

Does anyone have an idea on how I could plot them both together without getting this problem?