TPS voltage is bouncing around???
crusty old sensor could just have a bad wiper or
a worn spot where it's rested and chafed the
resistor stripe. Put the meter to it and see if you
can induce intermittent behavior by wiggling the
throttle. Also look for "flicker" on the +5 to GND
wires close to the sensor, in case you have an
upstream intermittent.


