bad engine mount causes a lot of "timing retard" problems. I have seen bad exhaust hangers, loose AC compressor brackets, rattling tranny cooler lines, etc. also cause it.
Since you are seeing 753, just add some fuel and see if it comes up...if not, you are gonna have to use that fp gauge you bought!
Long as you have a couple bolts on the bracket, it will be good...be sure you clean up the contact points on the bracket because the bracket is the ground for the module. I have seen several cars that ran badly and missed because someone forgot to tighten down the coil/module to the bracket, or the bracket to the engine.