Not sure if I'm leading you in the right direction, but I was getting code 42 up the ass when my knock sensor hit the fritz. However, that's a TBI Chevy motor, I don't know if the codes are the same for a carbed Olds.
NHowever, that's a TBI Chevy motor, I don't know if the codes are the same for a carbed Olds.
They're not. Code 12 is normally the code that indicates the computer is working, however if Code 12 sets when the engine is running it indicates a loss of distributor reference signal to the ECM. Code 41 will usually set simultaneously with Code 12. This could be either a bad wire on circuit 430 (the purple/white wire from the distributor to the ECM) or a bad HEI module. Code 42 will set if there is an open or ground in two of the other wires between the distributor and the ECM. It almost sounds like the four-pin connector to the distributor is loose or corroded. Failing that, it could be a bad module. The factory service manual has specific troubleshooting charts for all three codes.
finally figured it out after trying a ignition module....damn it was an ECM and double checked the timing just for the heck of it. it was a little off, that dist. hold down bolt is a real pain to get to. now the idle seems a little low, oh well