Abstract: A top stop-type fuel injector (10") for an internal combustion engine is disclosed. A pressure-time-delivery injector body (11"), barrel (12") and cup (13") are positioned in end-to-end relation. A retainer (14") extends around the barrel and secures the barrel (12") and cup (13") to the injector body (11"). A plunger (25") is positioned for restrictive movement within a plunger bore (24"). A return spring (29") is mounted within the upper end of the injector body (11") in concentric relation to the plunger (25"). A portion of the upper end of the injector body (11") is cut away to provide more room for adjustment of the injector (10"). External threads (80A) are formed on the remaining upper end of the injector body (11") adjacent the free end thereof. A collar (82) having mating internal threads (81) is mounted on the upper end of the injector body ( 11").