Lift pump pressure and voltage

coker6365

Coker6303's ***** Daddy
Dec 4, 2011
486
16
18
The standalone FASS pumps have an adjustable regulator. The FASS Titanium series pump systems with the filters don't. I'll start with the stretching the spring and replacing the check ball. I also have a voltage amplifier that is boost/signal referenced that I am going to install to ramp up voltage to the pump as boost/rpm comes in. I want to see how far I can push my single CP3. Once it's dialed in I'll post up some results.

What size pump? I doubt you have a voltage issue as typically it is the relief spring that causes the grief. You should have part # PS-1008 rated for 8-10psi. You can try stretching the spring first since the next spring up for use with that return fitting is PS-1015 rated for 45-50 psi. There is a dodge setup that uses MRT-1002 return fitting an spring PS-1001 rated for 16-18psi as well.
 

jpowel29

Member
Feb 1, 2008
780
0
16
Bentonville, Arkansas
I got a new spring and ball from FASS. I stretched the spring about 1/4" and didn't see any change in pressure (on the gauge). I am going to check fuel pressure up front with a mechanical gauge to compare the two. The ISSPRO 30psi electric gauge is new. Just curious to see how close the 0-100psi sending unit calibrates with a mechanical gauge. If those check out the same I'll swap springs.
 

ZeroGravity58

Well-known member
Mar 23, 2008
1,382
46
48
38
Maryland
I just finished installing my isspro fuel pressure guage. Right now my airdog is sitting at 13 psi at idle and drops to about 8 on a WOT run. That's still pulling thru a stock pickup. That on tune 4 with a single 10mm pump.