I have had a problem with my 87 760 turbo for about 3 weeks now. It seems to struggle to get going and has no power, seems to be missing s cylinder off and on. I took it to the shop for a diagnosis and he tells me it has the wrong brand of plugs and one of the plug wires is broken. When this problem started, we changed the plugs, cap and rotor, replaced the fpr and the fuel pump. Nothing seemed to make a difference. The plugs that we replaced had been there for a few thousand miles and were there when the problem started. So, that leaves the problem belonging solely to an instantaneous broken wire? Any input on this I would appreciate.