I would like to install a Walbro GSL-391 (190 LPH/50.2 GPH @ 43.5 PSI) lift pump between my stock in-tank lift pump and my on the frame 2 micron filter. I would be doing this to help push fuel through my aux. filter and I would not be using a pressure regulator. Would this setup supply enough fuel for a stock engine and would the pressure be too high? The idle fuel pressure of my truck currently is about 7 PSI, which is a little too low.
Thanks-John

 

You will have to regulate it. It has been done. The stock LP will be a restriction though. It will have a restriction in the volume of flow. Since you are stock, it shouldn't matter much.

 

Spooler- Would this be to regulate the volume, pressure or both?
Thanks-John

 

The pressure is too high and must be regulated. You could have problems with leaks. I think it would be a bad idea to run the two pump in series.

You say you presently have 7psi at idle, what is your psi at WOT? Are you measureing the pressure after the filter? If you are measuring after the filter and it does not drop below 4psi at WOT then you should not have any problems with your intank pump.

 

Pressure

 

7 PSI at idle is measured at the injection pump. At this time I do not have a gauge to measure PSI at WOT.
Thanks to all for your replies-John

 

The pressure drop that I have experienced on my old pump was about a 2-3psi drop from idle to WOT. On my FASS I get a 2psi drop at WOT. I replaced my OE pump when the pressure from the pump was starting to fall from the normal before it failed completly.

If you are not loosing any power at WOT and high RPMs, then you are OK with the intank pump. The CP-3 does not need much pressure to operate, it just needs the fuel it can draw on. Even 1psi will keep it running.

If you feel the intank pump needs replaceing then remove it from the tank and put a pump on the frame, but keep your pressure at or below 25psi.

 

Thanks-John