Question: Will My FASS Feed My Fuel Needs?

WisconsinHick1

New member
Mar 11, 2009
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Minnesota
I have a FASS 150 and I am running a 120% CP3 will my FASS supply enough fuel? I am seeing low actually rail pressure on my pulling tune and I am trying to track the problem.

I have a little fuel leak but nothing I thought would cause me to lose 8000psi on the actually rail pressure.
 

Dirtymaxx03

Active member
Aug 4, 2009
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do you have a fuel pressure gauge? I run a FASS 150 and Im on stock fueling, with stock fuel lines and on a 2800 tune i can put fuel pressure down to 3 psi from 11 psi. Running 1/2'' fuel lines from a sump to the cp3 may help you. Or maybe running a boost referenced regulator to increase pressure as boost raises. Or dish out for another 150 and run 2 lift pumps.
 

Dirtymaxx03

Active member
Aug 4, 2009
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No I don't have a fuel pressure gauge. I have 1/2 from top of the tank to the metal line on the motor.

if its at the top of the tank you are still drawing through the tiny factory draw straw. Id try a sump with a 1/2'' fitting and run 1/2'' from the fuel to the cp3.
 

Hot COCOAL

May the farce be with you
Jun 9, 2012
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Yea a sump and remove the factory fuel filter block if its not been done yet, wait, is the fass 150 a dual filter too, or just a pump? If it filters fuel as well, i would remove the factory fuel filter block, i would think it would become a restriction pushing double what was intended through it.
 

05smoker

I'm officially done!
Mar 30, 2007
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Lebanon, OH
Fix fuel leaks. If that doesn't do it, I'd be curious if it isn't the CP3.

The FASS 150 should be able to keep up to that, even with a factory draw straw.
 

Burn Down

Hotrodder
Sep 14, 2008
7,092
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Boise Idaho
High injector return rates can also cause low rail issues & still have perfect balance rates. But as stated above fix your minor fuel leak and go from there.
 

616samuel

New member
Apr 26, 2011
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Rockford, Michigan
fix the leak, then if it's still losing pressure could be in the tune... i run a fass 150, exergy 10mm cp3 and 100% over injectors, stock fuel filter still there and don't loose any rail pressure now...
 

WisconsinHick1

New member
Mar 11, 2009
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Minnesota
Well I tracked down my fuel leak and got that all fixed. Still getting low rail pressure. Now I need a gauge to check my supply pressure off my FASS.
 

Sledheadxp800r

That was only my tow tune
Dec 13, 2010
1,151
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CT
I think im going dual lift pumps in the near future. Maybe 2 fuelab 200gph pumps with internal 20psi bypasses? Not sure yet.
 

quadracer37

New member
Mar 31, 2009
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northern, IL
the fass 150 from trhe factory only runs 5lbs or so, usually not enough to support high horsepower or big injectors. you can get different spring from fass to allow it to run higher pressure. i run mine at 10-12psi and it supports 80 over injectors and 3 stock pumps. drops a few psi on hard runs only. also make sure your filters are fresh.