I finished the ls3 lq9 and tranny swap in the 91 ck3500 powered by the terminator x max by Holley with a inline fuel filter with a built in return with a Walbro fuel pump for some reason I keep loosing fuel pressure. What I would like to do is loose the inline fuel filter with the return and run the return AFTER the injectors so that atleast in theory they will get all the fuel they can handle and the extra will return. So my question is how do I do this any ideas a diagram would be great. Thanks in advance.

 

That's the way most return systems are set up.

Fuel from the pump comes into one end of one fuel rail; passes through; there's a short junction that takes the fuel to the other fuel rail; the FPR is at the far end of that rail; and the return line hooks up to that. The pump moves a constant volume of fuel, and the pressure builds up according to the total restriction; the regulator allows fuel to return, such that the pressure remains constant. (or at least, the regulator's setting; which varies according to engine operating conditions. Pretty straightforward. Much in the same principle as the oil pump.

No diagram that I can offer, really. It's too simple to need that.

 

Yes straightforward indeed. One other question for you is that an option on the stock fuel rail.

 

Not on stock ls3 rails unless you feel like doing some cutting/welding.
there is no “out” per say. Just one line in.
Holley makes a nice kit that can be set up with a double feed on the back and a y into a return on the front side. (You will need a regulator here)

 

How much power are you making?
the set up you have (if based on the vette filter/regulator) is good for 500HP with a decent pump. Can you explain about the FP loss?
mare you dropping during a wot pull?
or is it random?
If at WOT, what is the voltage at pump? Maybe a Boost A Pump?