i tested the iac and i got 50 ohms. the range from the book is 40-80 ohms. is this good or bad.

 

If its within spec, it means that the sensor is electrically "sound". It does not tell you anything about the idle air circuit, which must be measured in "counts" (or steps) with a scanner and the engine operating.

Shoebox's IAC test guide

 

50 is in the range of 40-80.