If you are certain that this is the exact motor you have:
Kysan SKU: 1124090 Mfg: 42BYG48B-18WC55W750C
MOTOR,STEP,NEMA 17,BIPOLAR,5.5KG-CM,4.2V,1.5A,D SHAFT
1.8 DEGREE,5.5KG-CM HOLDING,750MM WIRE,385X305X245MM
then no, the winding resistance is probably not 0.9 Ohms. Most likely it is 2.8 Ohms (4.2V/1.5A). The important specification is the current rating of 1.5A.
To what value have you set the current limit on your stepper driver? It should be set as high as possible, but to no more than 1.5A.