I have a 1990 740 GLE with the 16v DOHC engine. I replaced the head after a timing jump and after replacing the head, it has a slight miss and smells of gas inside the car. It is kind of sluggish when driving at highway speeds. I did an airbox mod to the car by taking the air intake duct (which is behind the grill) and cutting it off and turning it 180 degrees to make a sort of scoop out of it. Now I have ram air and the car runs quite a bit better than before. With the engine able to get more cool air, it is running better but still has the miss and the gas smell. Is there any fool proof way to test the fuel pressure regulator and be 100% positive it is good or bad? I am thinking it is my problem, but I work for my money and don't want to throw it away on parts I do not need. Thanks for any help.