Stand back from your engine bay and take a good look. Is your engine bolted to the frame? Mine isnt, its bolted to the frame using RUBBER mounts that do not conduct electricity. The only thing I found grounding the engine were two little ground leads and a few other small devices (electrical equipment odds and ends). What the factory gives you is only what the car need to run. Your spark plug needs a good ground to work to its full potential. All I did was ground the engine the most to the battery. The next line I will install will be from the alternator to the engine and the alternator to the frame because the alternator is what supplies the power when you car is running.