engcogod

Hey guys I've had a Fass II on my truck for about 6 months now and when I first got it my idle pressure was around 13psi and went down to about 11psi when I got on WOT. So I called where I got it and he sent me a new spring which then put me up at 17psi idle & no lower then 14psi at WOT... Over the past few months the WOT pressure has been dropping slowy and now is around 10psi with the Comp box untapped with the fueling set to come on early.. I upgraded all my fuel line from the tank to the Fuel Filter with 3/8" hose that came with the FASS II and yesterday I upgraded the hose between the Fuel Filter to the VP44 with the Vulcan Big Line Kit and my FP is being monitored between the Fuel Filter & the VP44....

So I am a little worried about when I tap the pump wire my FP will drop way below 10psi. From a stop pulling away from a stop sign on level ground it hardly moves at all maybe drop a pound or so... But as soon as I give it more fuel it drops to about 13psi and if I got to WOT it drops to 10psi... I have a message in to the guy I bought it from so I will ask him as well, but I wanted to see what you guys think as well.. It almost seems like there may be a restriction some where maybe in the pickup screen in the tank??? It almost has to be something in the tank because I just changed my Fuel filter not to long ago. Does anyone have any other ideas or suggestions?

Thanks, Engcogod

Clunk

Are you using a non-banjo on your lift pump to fuel filter plumbing?
Are there any screens that could clog on a FASS II? You should be getting better pressure than mine w/ my drilled out banjos.

AAmeeting

I have the Fass. I ran it to the factory filter and it showed a whopping 12 psi at the IP. Now that being said, I bypassed the factory filter and it is at 17 psi and I can only bring it down to 15psi. I think the problem lies in the banjo fittings. Actually I know it lies in those fittings, so get the vulcan kit or the scotty smart fuel and watch you fuel pressure soar. ch4 news

getblown5.9

i have the original FASS with the BIG line kit from tank all the way to the vp44 with no banjo fittings, and my idle is 15psi and WOT with 100hp sticks and comp on 5x5 is 10psi

havent seen it lower than 9psi ever...and rarely below 10...if it ever drops below 9 i will call for a new spring

Ben

Engcogod,

I had the identical set-up as you, Fass II and the Vulcan, have the about the same time on the system, and have experienced similar things as you. (Except I didn't need to change my spring.)

Here's a couple things I have found out with my set-up.

1. Fuel pressure is fuel level dependent. I don't let mine get below 1/2 tank.

2. As the pump broke in the fp dropped some. Pretty normal I'm told.

3. CHANGE the inline pre-filter to the pump. NAPA replacement part # 3270.

When I changed out my inline filter, I could hardly blow through the original one. The sounds of the pump also changed for the better. THere were times that it sounded like it was laboring.


Another observation I have is how quickly the FP recovers after mashing on the throttle. When the tank was below half, it wouldn't recover it would just stay 13 lbs until I let up on the throttle. Filled the tank and presto, that was gone. It would recover.

After changing the in-line filter the pressure drop is just a blip and RIGHT back to 16 lbs.

When running does your pump sound like it's running smooth? Every so often mine sounded like it was cavitating and I could also feel it when I put my hand on the pump.

I hope this helps you out some.

BTW - The Vulcan line and fittings from the Filter to the VP is pretty sweet isn't it?