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As someone that's been around a plethera of other platforms and formats I just couldn't see myself spending that much on a fuel pump add-on that other vendors have for sale and are selling. So I took it appon myself to try (and succeed) at building my own "Stage 3" LPFP kit. All in all I'm less than $500.00 bucks from start to finish. I'm posting this to try and help others that are interested in having one for themselves. Now I'm not the most professional (or detailed) at making directions and instructions but I'll try my best to be as detailed as possible. If anything seems confusing or anyone has questions I'll do my best to answer!
7.89 Fuel Line Hose Quick Release Connect to 3/8 (one straight and one 90⁰)(If you get the ones I posted they come with the male to 3/8 connector):
https://a.co/d/aFAo3Zk,
https://a.co/d/5HYHmI8
6x Small Nuts
2x Small Bolts
2x Rivets
Rivet gun
Extra wire (10g and 16g)
8mm socket
10mm socket
13mm socket
Assorted Torx bits
Wire coat hanger
Hammer
Some sort of punch tool
Pliers, needle nose
Drill
Drill bit (1/4 inch I believe)
Optional: heat gun (if you use heat shrink crimps)
Assorted crimp connectors
First things first make sure you have at least a 1/4 tank (makes it easier)
Pre-start/assembly: take the 3 hoses, the straight connector, the 90⁰ connector and the male to 3/8 connector and put them together (like in the picture)(I used a heat gun to warm up the 3 hose ends to make it easier to slip or over the barb fittings) Don't worry about the connector next to the male to 3/8 fitting I forgot to take it out the pic
New fuel pump assembly: Take the new fuel pump and slide the hanger/bracket over it, then take the adapter and install it on the pump (don't over tighten it or you'll break it, doesn't need that much torque there's an O-ring that helps seal it)
Step 1: pop the rear seat off (just pull should come loose) move it off to the side
Step 2: remove the cover thats covering the fuel pump. The 4 bolts should be 8mm
Step 3: Disconnect the 2 plugs you see on the fuel pump and set them aside
Step 4: Take your punch and hammer and "unlock" the fuel pump ring Ring removed
Step 5: carefully lift the fuel pump hat and disconnect the 2 harness that are under the fuel pump hat and put it off to the side (the 2 pin is the level sensor, the 4 pin is the fuel pump)
Step 6: Disconnect the hoses: there are 3 hoses that are attached to the pump. 1 on the pump itself a 2 that are apposed of each other that fill the bucket. For the one on the pump squeeze the tab and pull it off the pump, the other 2 slip off from there place (be careful not to break the tabs)
Step 7: (Forgot to take a pic in the vehicle but hopefully you understand what needs to be done) Take the needle nose pliers and disconnect the snap style connector that's next to the level sensor (it's a pain in the ***) what I did was I took the pump and turns it on its side with the tab facing up and slowly squeezing while gently pulling up on it. It will be full set in (not like his it is pictured, but that area)
Step 8: Once you have that piece disconnected remove the pump and basket from the fuel tank, be careful not to spill fuel everywhere
Step 9: Take the fuel pump hanger/bracket and mock it next to the OE fuel pump (the pump bag should sit level with the basket) on the flat side and take a sharpie and mark where to drill into the fuel pump basket, drill 2 holes.
Step 10: Take the hanger/bracket plate, 2 rivets, and 2 nuts. Place the rivet through the plate and nuts behind the plate and rivet the plate to the basket
Step 11: Take the top hat of the fuel pump and drill 2 holes next to the dumby nipple of the pump (make sure they are far enough apart that they won't touch easily)
Step 12: take the fuel pump harness that came with your new pump and crimp 2 D-rings/O-rings to the 2 wires
Step 13: Take 2 bolts and 2 nuts and run a wire from the harness through each bolt them through the hole in the top hat you drilled and bolt them now (don't torque it remember it's just plastic) (make sure to label which one is positive and negative)
Step 14: Take your fuel pumps and install them back into the fuel tank, start with the hose you made (the Y splitter) and take the end with the male to 3/8 fitting a plug it into the OE quick connecter. Next take the OE fuel pump and put it back in the fuel tank, push it over to the side and turn it so the bracket you rivited is showing, slide your new fuel pump in the bracket and spin the assembly with the new pump facing the front of the car, reconnect the connector your took off with your pliers
Step 15: connect all the hoses on the pump, the straight quick connect goes on the new pump. The 90⁰ goes on the factory pump. Make sure none of the hoses are kinked or binding
Step 16: Take your top hat and reinstall the 2 factory plugs you took off in the beginning and plug in the new harness you made to the new pump and reinstall the tophat back on the pump
Step 17: Reinstall the lock ring back in the pump
Wire Harness:
I installed the relay/harness in the trunk but you can do it anywhere that fits your preference. I ran the harness through a hole behind the back seat into the trunk (you'll have to remove the trunk carpet and plastic cover that sits in the rear of the trunk under the carpet)
I ran my ground (black wire) to the trunk/auxiliary battery and power wire to the main battery (but you can hooked both ground (black) and power (red) to the auxiliary battery) if your going to run it to the main battery make sure you use a 10g wire as an extension wire and to use the in line 30amp fuse as well
Run the orange wire to the positive bolt that you made on the new pump, use 1 of the 2 nuts left and tighten it down, make a new wire and run it from the negative bolt that you made to a ground, again use the last nut to tighten it down (I used the seat belt bolt as a ground)
The brown wire is your trigger wire, that's the one you have to run to the engine bay and hook it up to the Hobbs switch. I ran the trigger wire (and power wire) under the trim/carpet all the way to the engine bay, once you get up to the passenger front seat your going to have to pull the passenger side front carpet back and remove the foot trim panel. After that there a rubber harness rubber block that you'll have to poke through and stick the wire coat hanger through Where the red wire is where I poked the hole
Once you run your wire(s) through the hole (if your using the main battery as the power wire bolt it to the battery, if using auxiliary don't worry about it).
Take the trigger wire and plug it into the Hobbs switch (doesn't matter what side Hobbs switches are just open/close switches). Make another wire for the other side of the Hobbs switch and plug it to a 12V source (I bolted mine to where the jump start terminal is)
Hobbs switch:
Now my setup is probably different than yours, I have a vaccume block that I run since I have multiple things that need to see a vaccume reference. If you need a place to tap for a vaccume source you can take that nipple off the intercooler that's under the intake manifold, drill a hole and make 1/8th inch tap for the Hobbs switch (other method is buy the MAP sensor boost tap and run a vaccume block like I have)
ANDDDD that's pretty much it. If you want to test and see if it works throw 12V to the signal wire and measure the voltage at the pump (or take the pump hat back off and listen to it kick on)
As I said prior I'm not good at taking pics and explaining things but if you have any questions or confusions I'll be happy to help! Happy Fueling!
ADDITION: Use some kind of PEX/Single ear hose clamps on the 3 hoses (6 clamps in total) to secure the hoses. One of my hoses pooped off mid run and got me stranded😂. if you end up in the same boat as I did just remove the OE hose from the Y-splitter and put it back in the OEM pump until your able to fix it
Hello - Fantastic write up! and with pics! General question though regarding this mod.. Why would you do this install? I thought our fuel systems are enough? And for the install itself are you adding both pumps through the one hole? or is there another access port you are installing the additional pump into? Reminded me of a mod for the e46 330Ci and M3 that was getting fuel starved on long right hand sweepers under 1/2 of fuel. The G forces pulled the fuel away from the fuel sump.
Hello - Fantastic write up! and with pics! General question though regarding this mod.. Why would you do this install? I thought our fuel systems are enough? And for the install itself are you adding both pumps through the one hole? or is there another access port you are installing the additional pump into? Reminded me of a mod for the e46 330Ci and M3 that was getting fuel starved on long right hand sweepers under 1/2 of fuel. The G forces pulled the fuel away from the fuel sump.
Thanks,
Ian
Yes both pumps go through the same hole there's enough space when you put the OEM basket in to move it off to the side and install the second pump. As to why, this upgrades more so for people running ethanol and upgraded turbos, our pumps are great for pump gas but when running ethanol it tends to slow down/get sluggish at higher RPMS. It's more so a failsafe mod for the stock hardware people and a must have for people that want the most out of E85 (especially if you upgrade the HPFP as well)
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