Abstract: An integrally formed cylinder 2 having alternating magnetic 2b, 2d and non-magnetic portions 2a, 2c, 2e for use in an injector. At least two solenoid coils 12, 14 are disposed about the cylinder 2 to urge an armature 4b to open and close a valve 4a. The non-magnetic portions 2a, 2c, 2e of the cylinder 2 ensure that magnetic paths for opening and closing the valve are magnetically insulated from each other. The integrally formed cylinder 2 is leak proof and thus does not require O-rings or other sealing structures for sealing the fuel path 4e, 4f from the solenoid coils 12, 14. A protrusion 2z may be formed on the cylinder 2 to assist in positioning the solenoid coils 12, 14.