What is the correct procedure for the ECM to "Learn", and correct the timing?

I read that we should run the car "over 40mph for 15 minutes for the Learn Mode to initiate", but does that mean continuously or just peak over 40, and then continue to drive for 15 minutes fluctuating between high and low speeds (typical city driving)?


We have a freshly rebuilt 305 TPI which is idling fine, but seems to missfire under load and then can't find the idle and dies without a delicate feathering of the gas to stablilize it. The engine was kept stock, except for an LT-1 cam, and we removed (correctly, we believe) all the emission stuff, but went with a high flow cat and headers with an O2 sensor on the collector.

I've read several places that after we set the timing, there is a learn mode that will cause the engine to run rough. We set the timing at 6 deg., plugged in the tan wire, and the timing shot off the gauge. I believe this is normal. We had a shop read their scanner, Which told us that all the relays/sensors/switches are working properly, but couldn't read the spark since they didn't have the adapter for the wires and it being an OBD I system. We plan on running a scope on the wires tonight to see if any of the plugs/wires are the issue, but the car sounds correct at idle.

We are finishing a restoration project and trying to leave for Power Tour in Indy on Wed., we currently have 1.5 miles on the engine, so you can see my urgency and concern.

Wish us luck.