Abstract: A device for assembling a fuel injector assembly is described. The device includes a stand and a body coupled to the stand. The body includes a first arm and a second arm extending from a first side and a second side of the body, respectively, to receive and rigidly hold an adapter of the fuel injector assembly therebetween. The body further includes one or more grooves provided to adjust the body in a horizontal plane with respect to the vertical member. Further, the device includes a handle coupled to the body to position the body in the horizontal plane with respect to the vertical member. The device also includes one or more pins mounted on the vertical member, where each of the one or more pins engage with a corresponding groove and aid in adjusting the body in the horizontal plane with respect to vertical member.