...have some additional/follow-up info I recently discovered about the Wrangler JK fuel pump module to add to the conversation.

To recap, I'm building a 'primitive' 2014 JKU, no OE wiring/computers, stand alone dash/gauges, a Magnum 360, and a Holley Sniper 2300 series 2bbl EFI system. I'm testing my fuel system - checking for leaks, flow etc., before I drop the body on for the last time, and discovered something interesting. The Sniper has it's own fuel pressure regulator, set right about 63 psi, but I didn't know that the OE JK fuel pump module had its own internal regulator, apparently set at 60 psi. When I activated the pump, the high pressure side filled up to the Sniper and displayed 58 psi on my mechanical gauge...but I was not getting any flow out the return line. The reason was because the OE setup doesn't make enough pressure to open the Sniper regulator, and essentially turning the Sniper into a 'dead head'...which IIUC is how the factory did it, too. But, because this Jeep will see extreme conditions (including heat soaking), I very much wanted an active fuel return line to continuously circulate cool fuel through the lines and throttle body, eliminating what little heat possible. So, I needed to figure out a way to alter the OE regulator to allow the pump to make more pressure...thus allowing the Sniper regulator to function.

With that in mind, I pulled the module back out, took it apart all the way down to the pump and regulator, and pulled the regulator, and removed the pressure spring. I 'thought' that by removing the spring would enable the pump to flow at a higher pressure, but instead it reduced pressure down to about 30 psi.
Here's the basic fuel pump module -


These sending units/modules are very definitely 'serviceable'...tho having a few more pair of hands helps. Anyway, separate the spring-loaded top half, remove the pump housing, and then with 5 hands separate the filter assembly from the bottom (this was fun) -


this is what the OE Jeep (2014) wrangler fuel pump pressure regulator looks like -


and the pump itself, with the only part numbers I could find being REP500 07-04










Initially I thought I could increase the pressure by removing the pressure spring and remove the valve, but after cutting the end off the regulator and removing the spring the valve wouldn't come out...so I just left it there...






Reassembled and reinstalled everything, activated the pump...and now was only getting ~30 psi, and of course no return line flow. So, the spring is necessary to create pressure...but it's a spring...so if it were a tighter spring it might create 'more' pressure...so with literally nothing to lose, I pulled it all apart, inserted a nylon washer to fill in some of the gap to the plunger, and crimped the housing closed so the regulator would be at 'maximum'.


Slammed it all back together, hit the pump, and with what seems now to be a fully 'closed' OE pressure regulator the system filled all the way up, and made enough pressure to open the Sniper regulator, and now I have a functional return line and about 64 psi - all now regulated by the Sniper system.

So, learned a lot about how the OE system works...but I'm not really a big fan of smashed-together pressure regulators...and while it would probably function as-is forever...I looked into regulators that might have a higher psi rating...and I think I found them. DeatschWerks make 4 regulators rated at 65 psi, and they all look identical to the JK unit, the differences between them being the application they are for...but they all look identical, and according to the vendor are all identical save for the application...so not sure why the different part numbers...but hey it's progress.

SO...to keep the 'closed' regulator in it now...or install a DW unit and hope it is actually a true 65 psi unit - that is the question.

https://www.summitracing.com/parts/dwk-6-45-m54

I'll update the post after I have any more relevant info. Thanks
- Sam

 

Also, these Evil Energy fittings are a direct replacement for the OE old and brittle plastic fittings, and work awesome -

https://www.amazon.com/dp/B07GB2R77C...n_title_4&th=1

...paired with these 3/8 hose fittings -
https://www.amazon.com/dp/B0DC6C5CTD...fc2hhcmVk&th=1

- for this main fuel output port -


these are aluminum fittings that 'assemble' onto the port, with internal o-rings - work awesome -






my setup, with the hp filter right there for easy access/removal via the access panel directly above -