So much for trying to be out of sight/out of mind with deletes.
Kennedy is a good way to go, even more so if your getting good prices.
The problems you mentioned with FASS happens when you go with bigger than the FASS 95 or AirDog 4G100 lift pumps.
You only need bigger liftpumps if your engine is producing more than 600 hp.
They claim 500 hp so they can sell you more stuff.
The 150/165 puts out to high fuel psi usually in the 12-13 + psi to the engine which is to high and causes the issues you mentioned in the return line including excess air.
Safe psi for the Duramax is between 8-10.
The sump pulls from a different location away from the stock pick-up and return.
What the companies don’t/won’t tell you is having a sump does nothing to lower the psi to the engine, but you’ll still have a “Niagara Falls” fuel return.
I went from a AirDog FP-100 to a 4G-165 motor had these issues, then swapped back out the 165 motor for a 4G-100 motor, no more issues, no excessive air.
The idea behind the return is fuel is always available for what’s needed at the engine, what’s not used returns back to the tank, which I do like.
I don’t feel the reasons they claim for the air and polishing is really actual facts.
Fuel is not heated up with this process, but it is filtered a little more returning and returning thru the LP, which IMO is a good thing along with having fuel always ready and available when needed at the engine.
2007.5 GMC Sierra 3500 SRW L.B."BLACK" C.C. 4X4 LMM Z71
DIY stock airbox mod, aFe ProGuard 7, OEM drop-in
EFILive ECM ATP - Heavy Tow Tune with Turbo Brake.
EFILive TCM Duramax Tuner
DHD Cold Side High Flow Intake Pipe, DHD PCV Re-Route, AirDog 4G100
Castrol Hypuron/Vecton 15W40 synthetic blend oil
Donaldson P550832 2 qt oil filter
2007 Yukon Denail "BLACK" 6.2 gasser
DIY stock AirBox Mod, K&N, Airaid intake, EFILive TCM only tuning
Last edited by D_R_C; 09-28-2019 at 03:12 PM.