GT, 3.8, odd miss

After operating for various lengths of time ( usually between 10 to 20 minutes after cold starting), my GP will have a hard momentary miss as if turing off the ignition for just a moment. The tach will drop out and the motor will them continue to run, athough it seems, with slightly less power.
Any thoughts?
Don't know if this is related, but on a rare occasion, after a short trip, it won't want to start. Eventually it always does start but not until many attempts. This probably happens, perhaps, once every 50 times of operation. Most times will fire up instantly.

Welcome to AF.

Based on your symptoms you have a crank position sensor going bad.