[误] It is time that we stop the machine and find the trouble.

[正] It is time that we stopped the machine and found the trouble.

注：It is time that...表示“是......的时候了”，其后的从句应采用过去时态，这是虚拟语气的要求。

参考例句：I stopped at the square and got out to stretch my legs 我在广场处停下来，下车活动活动腿脚