how many ignitian coils in a 8 cilinder car

Hello, to answer your question, there are 4 coils on your Eldorado. Each coil supplies spark to 2 cylinders. The following cylinders are shared by a coil: 5-2 3-8 1-4 7-6 However, "guessing" that a coil is failed is not the best idea. First of all, can you verify or even know what cylinder or cylinders could be causing the rough running, if that's even what it is? Second, for the affected cylinders, have you checked the related spark plugs for condition? Third, have you performed a manual compression test of each cylinder to see how the base engine is? Before guessing at anything, it would be prudent to due some basic testing to see what you're getting into. If you had a base engine issue, would it make sense to throw hundreds of dollars at coils that won't help? Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops