Got a problem with my ingition timing base setpoint and advance, I have resourced about every thing I can find on this topic, so now I am looking for experience to help out. Here is the problem...I have the ingition control module with BID distributor, factory base timing calls for 3° advance with vac disconnected and 550 engine rpm but once the engine rpm is increased the timing is retarted by about 8 to 10 degrees up to 1600 rpm when the mechanical advance kicks in. Have installed a new distributor because the vac advance on the old was shot. Vac line to the distributor is connected to the ported advance not the manifold vacuum. Starting to guess but I am point to either the coil or the ICM as the culprit. Hate to start changing parts but might have to. Thanks DAG