The 370z fuel pump assembly is vastly different than the unit found in the 350z in terms of shape and packaging. However, it does perform all the same tasks in the same method, only with a couple upgrades in functionality. The first thing we noticed is that its TALL. The second thing we noticed, the swirl can is awfully limited in displacement, most of which is displaced by the pump housing and internal filter.

This unit is a lot more obvious in its features unlike the 350z which takes a deeper look to figure out since most of the plumbing is internal.

Following the 350z theme, this unit pumps into an internal filter housing, and from the filter housing it exits the tank. The fuel pressure regulator bleeds pressure from the filter housing, and it dumps into channels that lead to a pair of venturis. One venturi to siphon fuel over the tank, and the other venturi firing into an inlet on the bottom of the swirl can to promote refill.

Here you see a similar fuel temperature probe. The swirl venturi is in the black housing in the lower right of the photo.

The plumbing is mostly external on this assembly. Notice the fuel line that exits the fuel pump output and makes a u-turn directly into the fuel filter housing inlet.

After the fuel flows thru the filter, it exits the filter housing via the teflon line leading off the left side of this photo, and goes straight out of the top of the assembly to head to the engine.

Here is where the secondary functions kick in. What you are looking at is a side view of the filter housing, notice the exit line leaving off the left of the photo.

The metal object in the top center of the photo is the top of the fuel pressure regulator. It is similar in appearance to the 350z, but it is not the same, so our previous regulator pass-thru plugs will not fit this for return fuel conversion.

Fuel bleeds out of the filter housing into the side of this regulator, which dumps downward (to the right in the photo).

Notice that you cannot remove this regulator without modifications to the assembly which will require cutting off the part that holds it in place.

The 370z fuel pressure regulator outlet oriface (bottom) measures to about .090" compared to the 350z counterpart (top) that measures .065".

This is a sign that its possible that the factory regulator will be able to support a fuel pump upgrade without modifications. The 350z regulator requires drilling the outlet to about .110 when putting in a 255LPH pump. The .110 may or may not be overkill, so its hard to determine at this time if the 370z regulator is going to be 255LPH friendly or if improvements will need to be made.

The good news, is that you can actually get to the outlet oriface on the non-removeable regulator in the 370z should it need oversizing.

This part can be removed from the assembly. The location of the red circle is a press fit into the channel that the regulator dumps into. The blue circled region below it presses into the refill siphon that is mounted to the bottom of the can. So in effect, this is a T fitting that splits the return fuel to the venturis.

The green circled barb is where the siphon hose connects. The yellow outlet is where the siphon venturi dumps.

The last thing of significant interest is this guy here. This is a return pressure relief valve. This will either help us out with upgrades, or make no difference at all.

In the 350z, when you upgrade to a 255LPH fuel pump, return fuel or non-return fuel you still need to enlarge the opening of the fill venturi. This is because the quanity of fuel being dumped by the regulator at idle is significantly higher than with the stock pump, and the 2 venturis alone are too restrictive for the regulator to do its job since where it dumps is completely backed up with pressure.

This valve will open when the pressure gets too high, so that the regulator can do its job. However, when it opens, it may relieve too much pressure and kill the venturis. If that is the case, we will have to open up the venturis anyway to keep the valve from opening as much as possible.

Remove the retaining clip holding the top plate to the fuel pump assembly. It will require a pair of small tools to pry it outward on both sides.

Set aside the retaining clip, and the spring and spacer. Be careful not to misplace, they are important.

Remove the surge canister from the fuel pump assembly by spreading the pair of locks apart on either side of the assembly while gently pulling the canister off. It may require a little bit of rocking the canister while pulling on it. Be very careful not to break off the tabs for the locks.

Remove the blue and black wires powering the fuel pump from the top flange, and cut the hose leading from the fuel pump to the filter assembly.

Release the pump from the assembly by pressing the two tabs circled in red and rotating it free. It can now be dropped out the bottom of the filter housing.

Remove the remainder of the fuel pump hose by using a blade to split open the hose along the barbed output of the fuel filter inlet. Once its split open vertically along the entire barbed fitting it will come off easily.

This is what the assembly should look like now.

Inside the fuel pump bore, use a blade to cut the 3 attachment points for the OEM fuel pump retainer ring. Use a file to file the 3 areas smooth. The result should look like this picture.

Install the OEM pump's pickup filter to the Walbro GSS342.

Install the Walbro GSS342 using the CJM Fuel Pump Installation kit by referencing the following series of pictures.

1. Install billet clamp by sliding it all the way down securing post and tightening post clamp allen screw.

2. Install length of hose into the billet clamp, but do not tighten.

3. Install length of hose onto the fuel filter inlet barb and tighten clamp.

4. Install U-Bend pipe to both hoses and tighten clamps.

5. Lubricate fuel pumps output barb, and slide into the assembly, engaging the fuel pumps output into the hose and billet clamp assembly.

6. Rotate the fuel pump until clocked properly and center in the assembly, and tighten the final clamp securing the hose to the fuel pump output barb.

The wiring pigtail supplied by Walbro will need to be used now. 2 spade connectors are to be crimped to the end of each wire and plugged back into the top flange.

NO PHOTOS AVAILABLE YET

The factory fuel pressure regulator needs to be removed. In order to remove it, much plastic needs to be trimmed away.

Much care needs to be taken to only remove the plastic required. Use the following photographs as reference.

Install the CJM Regulator Fitting Clamp using the 2 supplied bolts.

Make sure it is facing the correction direction. It will still fit when upside down. However, if not facing the correct direction, it will not leave the ears of the fitting in the correct location.

Tighten the bolts gently and evenly.

Drill a hole directly in the center of the top flange. The diameter of the hole needs to be snug for the bulkhead fitting to seal correctly.

Reassemble the entire unit and connect the hose between the bulkhead and the CJM regulator fitting.

Make sure that you can compress the spring loaded assembly about an inch without the blue hose becoming kinked.