I was having some lower fuel pressure with my fuel boss: 16 idle and down to 10 full throttle. So I added a couple shims to the return valve and now I'm at 22 idle 17 full throttle. Contemplating taking a shim out, is that pressure too high? 

Thanks

I would personally be comfortable with those pressures.

Doesn’t fuel boss pressure usually go up with engine rpm?

Think my return valve spring was weak from the get go and has gotten weaker over time. 

Use to sit at 18 idle and 16 wot. The drop happens initially around 1800rpms and climbs back up in the higher range. The drop slowly got farther over time till I put some more shims in and slightly stretched the spring a bit. Think I'll keep an eye on the pressure so it doesn't get any higher. Wondered if fueling from hot rod VP44 and 7x012s had anything to do with it

One of the things folks that have them brag about is fuel pressure going with rpm. There is part in the system the gets debris that causes the drop. At least from what I have read. Definitely no expert on them. 

Ya I had trouble in the past with debris getting in the the return valve holding it open. The strainer alleviated that. Really like the system, just need to get the return valve in order

My Assassin is opposite... 14 idle  22 ish max, builds psi very quick 

 

Edited March 28, 20205 yr by wil440

my fuel boss idles at around 19-20, increases to about 25-28  (i stretched the spring a bit when i installed)   you may have debris in the check ball valve.

I probably have taken the valve out a dozen times now to clean it. When it would get stuck the pressure would drop to around 10psi and climb up to 18 through rpm range. 

Now I have the strainer in place so not having a problem with things getting stuck

@CAMG3X have you thought about pulling your tank and cleaning it really good? 

Have thought about doing that if it keeps up. The only debris that I was getting in the valve was rubber shavings left over from the install. Hoping the strainer will catch the rest for now. Really like the whole system. My pressure has stabalized right around 20, lowest I've seen it is 17 getting on it. 

In the future after putting the fitting on hose flush hose with water and blow out with air. Helps get rid of crap.