I want to monitor fuel pressure. Wouldn't I need to install the guage on the return side to tell what pressure is at the injectors? I assume this is the side of the fuel circuit AFTER the fuel pressure regulator. Installing on the inlet only checks the pump, right? Does the CFM Tech adaptor install on the supply or return fitting?
I may be over thinking this but I'm about to start trying to tweak for mileage and there's no such thing as too much information.

 

It should go on the feed side as close to the TBI unit as feasible. Think of it this way: the regulator controls the pressure on the feed to the injectors. It does this by allowing any excess fuel back to the tank via the return line.

The feed side of the TBI uit is the drivers (US) side.

RBob.

 

 

Is the regulator downstream from the injectors?

 

That works. As long as the regulator inlet is plumbed from the outlet port of the TBI unit. The bottom port of the regulator goes directly to the return line back to the tank.

Also remember that the liquid filled gauge is only accurate at room temperature (72 F).

RBob.
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Yes. The fuel enters the TBI unit via the feed port. It channeled to the area at the bottom of the injectors, then moves into and up past the injectors to another channel. This channel goes to the regulator which maintains the pressure on this incoming feed from the injectors.

Whatever fuel is not required to maintain the pressure goes through the regulator to the TBI unit's outlet/return port. Which returns back to the tank.

RBob.

 

Great. Thanks, RBob

 

X2 RBob. The regulator I posted the pic of is going to be placed on the return line, attached to the frame just above the fuel filter. I need to place it out of sight since my Suburban is a California vehicle.