An electronic tension meter was used to detect the weft tension of an Investa PI65 air‐jet loom. The voltage signals of weft tension were stored and analyzed by a microcomputer. The air‐jet pressure and weft yarn properties are found to affect the weft drag which in turn influences the insertion time of the stored yarn. Good weaving performance can be obtained if the outward movement of the toothed rim in the storage drum coincides with the timing of the stored yarn just run out.