Your symptoms dont sound like a typical Crankshaft or Camshaft sensor failing....

Doc's suggestion to look at vacuum lines and TB are good....leaks are semi-common...

I have had two scenario's that causd a similar symptom to yours....
1. The rubber gasket between the TB and the SC cracks/splits at the joint with the metal plates in it...
2. The TB was acting like it wasnt working right... did a Thottle reset and it cleared the issue. (I have had this happen to me two different times after working on the car)