grzpdlr

Installed a FAA about three years ago, ignored warning about also installing a fuel pressure guage. Finally got around to installing the guage this weekend and am reading about 13 psi at idle and drops rapidly when I punch it to about 8 psi.
My question is, is this likely a "tired" spring in the FASS or do I have some line restriction? Changed both FASS filters, no difference.
Thanks for the help.

zukgod1

What size fuel line you running on it?

dan

G-NOTE

You can order another spring from DPP,they do get tired but you might want to ask them about the life of the motor on the fass unit...

micah

do you have more information to share? I recently installed a FASS and hold ~20psi at idle and no less than 16 @ WOT. I really was thinking I spent the extra $ so I wouldn't have to worry about that gauge again.

crobtex

I don't know of anything electrical or mechanical that lasts forever.

rockjeep73

The brushes on the older units are known to wear bad, might want to check and/or replace them.

micah

fair enough... but I was hoping for more than 3 years. He sort of implied he wasn't surprised.

Diesel-Dan

Try this.....Get a 5 gallon bucket and fill it with diesel. Take your return and suction and put them both in the bucket. This will take your tank out of the picture. Try to see if you pressure goes up from what it was at idle before. If it does, might want to check your fuel pick up in your tank. Over time that screen can get clogged with junk and might need to be cleaned off. OR while you have the tank off, install one of the 1/2" fuel pick-up's that you FASS dealer can get you now. This would elimiate that issue for good.

ALSO....what type of gauge? Electric, mechanical with isolator? Check EVERYTHING on that gauge install and make sure its reading correctly. Get all the air blead out if its mechanical. Look for any leaks...as Micah can tell ya.....it can happen to the best of us!!!

If you pressure does not increase, you might want to contact the dealer you got your system from and see what suggestions (in person) they can help you with. OR post on here...and we will try to help ya out! haha....

If you sent in your wnty info.....you should have a 4 year wnty on your hands.

Anyone not useing a fuel pressure gauge on a Cummins, FASS or not, is playing with fire! Its like a coolant temp gauge....its not much to look at until there is an issue!

grzpdlr

It is a mechanical, with isolator. instructions say fill guage side with antifreeze and not worry about filling the line to the guage if its less than 6 feet. I did anyway but know there are bubbles in there, are they going to effect the reading?

Diesel-Dan

Sorry...i should have made myself more clear. What i ment was on the diesel side. There should be a Bleed screw (Make sure its in the up position when you crack it.) to open to bleed off air. If you get excessive amts of air, it could throw off the gauge and make it read slighly low. The anti freeze side, just fill the isolator....and that will work....it has for me at least!

If you have a leak...the pressure would slowly bleed off and your gauge would read low to nothing. But you dont seem to have that issue...or might have the start.

ALSO...i dont know if you did the upgrade or not, but there was a issue with the older FASS units with the 3/4" Buna Ball under the T-Block. This ball was too large and would sometimes stick and cause the unit to loose prime. A 5/8" ball was used to correct this problem. Affected SN# were before 2546. Wouldnt hurt to get this upgrade kit if needed. (Might as well get a pressure spring as well to freshen it up). Contact your dealer on that one. If you sent in your wnty card, this might be covered under that (The older units actually only had a "no" or 2 yr wnty depending on if you sent in your wnty card. The newer ones come with a 2 or 4 depending on the card. Check your SN#).

Made an edit......was was mistaken on one part of information.....

grzpdlr

terrific info!!! Thanks Dan

grzpdlr

Anybody else have this problem, trying to order the parts Dan mentioned, tried three suppliers, nobody wants to mess with such a small order. Yes, I did contact the guy I bought it from, one of the three I contacted.

Olratlr

That Figures! Who did you buy it from?

Diesel-Dan

Here, make it easier for them:

5/8" Ball: 1901-625-5939
Upgrade/Most current Motor and T-Block: RP-1001 (95GPH) RP-1002 (150GPH)
Pressure Spring for FASS in the Dodges: PS-1002

I dont have the part numbers for the O-Rings infront of me...but all they need to do is ask for all the associated o-rings and they will get them. I dont see what is so hard about ordering these parts. If they are a dealer...they should have a price sheet with all these part numbers.

I upgraded my motor, T-block and Pressure spring and my press went up to 22PSI (From 14.5PSI). I am going to mess with it somewhat...but this should not hurt anything.

PHD_WHITETRUCK

buddy of mine has a fass and he aint had nothin but problems. since he got his it has went got completely redone and every thing. sign me up for one of them. i can bye a bunch of carter pumps for what that cost and throw them away when they die