If it's similar to the TBI Tahoe I worked on it sits inverted in the injector pod.It's the top bracket on the TBI unit that retains the two injectors. You must remove the inj pod to get to the f/reg. First remove thetwo steel fuel lines thenthe larger torx screws that holdthe podin place. Flip it over and you'll see the retainer cap that houses the f/regulator. Napa sell a rebuild kit for about $25 and includes a new fuel pump regulator diaphram, injector orings and instructions.

 

lovely, at least it shouldnt be to hard to fix or replace. thanks sewer