my friend just bought a s600 v12 for £2000, yes £2000, problem is it only runs on one bank the right 6 have no spark. both coils have power and car travelled several hundred miles on limp home (70mph). i know this car kills a bank for economy, and as the engines are supposed to be indestructable, i was wondering if it could be a minor prob with this function

or has he just bought a £2000 2 ton shed?
any help would be much appreciated.