"As we know the liquid engines in KSP can ignite for infinite times at any moment as you want, which seems a bit making life too easy." This words  has been said ages ago by HoneyFox and i completely agree with him. But his mod has not been updated for ages, also behaviors has been broken by KSP version changes and i have decided to rewrite. All inner logic has been changed but functionality is about the same, according to my vision. Well. What this  mod can? 1. Each engine