What happened to me, I want to start Engine #2 first, but when I click on the starter of No.2, nothing happened, so I have to click on No. 1 instead, however, the N2 goes up to 13 and stop, engine could not be started no matter how many times I tried. Any clue for me?

Do you have suffiencient bleed air? I ask because the APU is powered on the left side, and if you don't open the ISO valves, your plane won't have enough air to start.