He he, I'm having just about the same problem. Fairly new TPS, junkyard distributor, and I checked my timing before goin' on a wheelin' trip, and lo and behold, with the connector jumped, I have 35 degrees advance! WTF! Thought maybe I installed the distributor wrong the last time, it was fine. TPS may be the culprit though as I couldn't get two of the readings to jive, don't recall the exact names of the pins on the TPS... 2nd from top and the bottom pin yielded no continuity, where it should've had less than 2.3K Ohms...

Hmmm... I did gently wash the motor recently, but was careful to avoid the TPS - maybe some correlation?