The fuel pressure on a 1991 Chevy pickup varies depending on the engine. There's no single answer. You need to know the specific engine (e.g., 4.3L V6, 5.0L V8, 5.7L V8, 6.2L V8, diesel) to determine the correct fuel pressure specification.
To find the correct fuel pressure, consult your owner's manual or a reliable repair manual specific to your truck's year, make, model, and engine. These manuals will list the proper fuel pressure range for your engine.
