I'm having some weird things happening on my Electronic Fuel/Spark Control system on my 318. When the throttle body is at hot idle, a ground is put on the carb switch and the EFCS module is supposed to stop all vacuum advance...or at least the book says that! I'm getting instances when the module is providing vacuum advance at idle, even with a ground present on the switch lead. The module itself is seeing ground on lead N3, violet, which goes to pin 7, conn. 1 of the EFCS board on the air cleaner. Sometimes, I get advance, sometimes I don't. The manual states that there should never be vacuum advance whenever there's ground on pin 1-7 from the switch.
Anything I'm overlooking here, except a bad board? This is a CA car,
7° BTDC @ 630 RPM, not the 49 state version. Does engaging AC cause the spark advance to come on, or is there another sensor in play here? If I just pull the hose off the transducer on the air cleaner mounted housing, I set the timing for 7°, and then...sometimes...I get a fast idle indicating advanced timing, and then it'll drop off. Hmmmm!