Yesterday I swapped out the stock regulator spring for the Ford "Blue Spring" upgrade (Motorcraft Part # 3C3Z-9T517-AG).
The truck jumps right off the line now. Very little lag when you jump on the accelerator. Haven't hooked up a Fuel Pressure Gauge yet so I don't know what the pressure was and as soon as I get some extra coin I'm going to get one. I figured it can't hurt to do the upgrade nonetheless.
First thing I did was remove the 3/8" return hose to the degas bottle ( if the engine is warm/hot first release the pressure by unscrewing the cap slooooowly ), then take out the air filter and connection to the turbo which also requires the disconnection of the electrical connector.
Then I disconnected the black plastic Intake Tube and loosened the bottom clamp and swung it up out of the way. Best to do this when the engine is warm so the plastic tube pulls away from the intake elbow a lot easier. Otherwise its tight and you may have to heat it with a hair dryer.
Then rather than disconnect the upper radiator hose, I wrapped a piece of cord around it and dropped it down the engine compartment to the ground. I pulled the hose down out of the way and tied it off to the front receiver. I would have tied it to the tow hook but the Bodiak front receiver is bolted to it.
Now I had clear and easy access to the side of the Secondary Fuel Filter Housing. Remove the fuel filter cap and secondary fuel filter. Get a clean turkey baster and remove as much of the fuel as you can from inside the secondary fuel filter housing. Then disconnect the fuel return line from the regulator cap.
Note: some kits do not contain a new Regulator Cap.
You're gonna need a Torx T27 socket wrench to get the (4) bolts off the side of the secondary fuel filter housing to remove the regulator cap and keep your thumb on it as the spring inside is under tension by the cap. Keep this in mind when you re-install the new regulator cap. Oh yeah, Put a rag under the cap as you remove it as there will be some fuel that will spill out.
Once you get the regulator cap off the side of the secondary fuel filter housing you'll need to put it in a vice to get the threaded fuel line connector off it. Replace the o-ring on the fuel line connector. Remember
: Some kits do not contain a new Regulator Cap. You may not have to disconnect the return fuel line to the Regulator Cap to replace the keyhole shaped O-ring. There should be enough play in the line to swing the Regulator Cap away from the Secondary Fuel Filter Housing to get at all the parts.
Once you have installed the new blue spring and brass cup and puppet valve into the side of the secondary fuel filter housing, install the new or the original regulator cap use your thumb to depress the spring tension and tighten the torx bolts (don't tighten the torx bolts too much or they'll snap and you'll have a real big problem on your hands).
Then install the fuel line connector on the side of the new regulator cap. Again, I applied a light coat of clean engine oil to all the o-rings used.
Reverse the dis-assembly process by installing the black plastic intake tube and torque upper and lower clamps to spec, re-install the air filter and related parts and electrical connector, release cord from upper radiator hose, etc. Double check everything.
Cycle the ignition 3 times before you crank it over to make sure you prime the fuel system.
Turned out to be a pretty easy project. Took a couple of hours. Plus I was interrupted by a long phone call (Mom Called). But it was a nice day and the beers were nice and cold. Now the truck runs great. Not that it didn't before but I definitely notice a big difference when I jump on the GO peddle.
On Edit: After installation of a Fuel Pressure Gauge I'm running 70-74Psi at idle and 65-68Psi WOT.
Comments below each photo.
Fuel Regulator Kit 3C3Z-9T517-AG ($51.70 + $9 Shipping from Tousley Ford)
Regulator Kit International Part # 1843065C98
Note: For some reason the new brass cup is not in this picture. Must have been under the bag or the piece of paper.
3/8" Return Line to Degas Bottle Disconnected, Air Filter Removed, Intake Tube Disconnected and Upper Radiator Hose Pulled Down.
Secondary Fuel Filter Housing. Filter Housing Cap Removed, Secondary Filter & Fuel Removed. Return Fuel Line Disconnected.
Regulator Cap Removed, Stock Spring, Brass Cup that the Spring goes into and other nylon part (puppet valve?) with an o-ring on the back side of it to be removed.
Parts to be replaced have been removed from swcondary fuel filter housing. Make sure you replace the brass cup that goes into the fuel filter housing that the blue spring goes into.
Old regulator cap with fuel filter connector removed. You need to put the regulator cap in a vice and remove the connector with a socket wrench. Then replace the o-ring with the one that came with the kit. Coat the new o-ring with some clean engine oil. Remeber: Some kits do not contain a new Regulator Cap. If this is your case by pass this step.
New "Blue Spring" & Stock Spring Side By Side and the old brass cup.
New Regulator Cap Installed with other new internal parts. Install the return fuel line connector with new o-ring at this point and reconnect return fuel line. Reverse the process now by reinstalling the secondary fuel filter, cover, plastic intake tube (torque to specs), air filter, etc. and remove cord from radiator hose. Double/Triple check everything then Cycle ignition 3 times to prime fuel system before cranking engine.
Old Parts Removed
Now get out there and do it