I want to thank you for your diagram of firing sequence for the 87' Buick Grand National. I finally started to do a major spring cleaning in September since I had my all original fully loaded T-Top, and digital dashboard 87' GN in the garage for 11 years. I do start the car about two or three months at a time to keeps thing loose. I replaced valve cover gaskets, had the original radiator boiled, internally wire brush the copper tubes, and then solder the end joints. I replaced the oxygen sensor (AFS22), but that gave me a code, so I replaced back the original (AFS20), no more code. Thanks again, gnonyx
