Check your meter's resistance range. The <2.3 reading is 2.3Kohms (i.e 2300 ohms):

http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml#TPSAdjustment

For timing, once the TPS is reading under 2300 ohms at idle, install the timing check jumper and use a timing light to set the timing (by rotating the distr.) to 5 BTDC.