Topic: Fuel pressure regulators

[Jeffy]

Came across this on another forum while looking at something else.

In case you need more pressure, there are fuel regulators that fit Jeep fuel rail with no modes, Chrysler 4418850 or 5277829 or 5277864.

This regulator will bump the pressure up to 40 idle 48PSI at WOT.

[VA_YJ]

With the stock FPR delivering about 31 psi at idle and 39/40 psi at WOT, I would think these parts would not be suitable for a 4 banger unless you had significant mods (e.g., turbocharger or supercharger).

[sharpxmen]

With the stock FPR delivering about 31 psi at idle and 39/40 psi at WOT, I would think these parts would not be suitable for a 4 banger unless you had significant mods (e.g., turbocharger or supercharger).

could work if you match it with injectors (so you get the correct flow) but with stockers is probably a bit much and most likely not enough if you have forced induction (I mean with stock injectors).

[dwtaylorpdx]

Would be a easy thing to fiddle with though... :D

Easier than some of the other silly stuff I've had to fix lately...

[jmo69]

Would this FPR work? Looks like it goes in line. Could take some modifying with hard plastic jeep lines. Also, what to do with the one on the rail? Looking to do the #19lb injector upgrade.
http://www.ebay.com/itm/UNIVERSAL-JDM-BLUE-ADJUSTABLE-FUEL-PRESSURE-REGULATOR-FPR-WITH-PSI-GAUGE-/281548001947

[Jeffy]

Would this FPR work? Looks like it goes in line. Could take some modifying with hard plastic jeep lines. Also, what to do with the one on the rail? Looking to do the #19lb injector upgrade.
http://www.ebay.com/itm/UNIVERSAL-JDM-BLUE-ADJUSTABLE-FUEL-PRESSURE-REGULATOR-FPR-WITH-PSI-GAUGE-/281548001947

No, problem is to run an in-line FPR you need to remove the FPR on the fuel rail.  Sharp made a dummy FPR for his.  Although, I wonder if you could just remove the return all together and swap in a TJ fuel rail and plug the return on the tank.

[jmo69]

Ok. Yeah, I read Sharp's write-up. The dude's got serious attention to detail. Maybe it would be simplest for me to get the Hesco.

[jmo69]

And just curious, I can't just leave the old FPR in and plug the vacuum on it if I was to put an in-line FPR in?

[jmo69]

Sorry to keep asking dumb questions, but am I correct that he went "IN" through the schraeder valve is? Where you would normally test the pressure? And why?

[Jeffy]

Sorry to keep asking dumb questions, but am I correct that he went "IN" through the schraeder valve is? Where you would normally test the pressure? And why?

If you go to the last page you can see he went with a TJ fuel rail and removed the return-line.  This simplified things as the new return is on the FPR.

http://4bangerjp.com/forums/index.php/topic,7916.15.html

[jmo69]

That is a great write up! I still have a couple more questions though...
If I use the YJ rail, and plug the stock FPR, and plug the return line, (because the return will go off the adjustable FPR), would that work?
Also, what pressure am I looking to use with the #19lb injectors?
Thank you for your help!

[Jeffy]

Well, I think doing that would add a potential for leaks.  Though no more so then with the FPR there I guess.  You'll also have to use the schrader valve as your input which works but really it's not designed for that.  You'll need adapters like what he was running.  There's really no reason to remove the return if you don't have to.  If you didn't want to have to get another fuel rail then you could probably weld a plate the FPS opening over then add the FPR after the hardline and run it to the rail so it looks clean.

IIRC, the fuel injectors want 43.5 psi which is why he set his at 44 psi.

[sharpxmen]

That is a great write up! I still have a couple more questions though...
If I use the YJ rail, and plug the stock FPR, and plug the return line, (because the return will go off the adjustable FPR), would that work?
Also, what pressure am I looking to use with the #19lb injectors?
Thank you for your help!

Thanks,

I did that too (block the return) but actually plugged the return nipple, if I recall correctly I threaded it and put a metric 6 or 1/4'' with teflon tape on it. you can plug the return line as well, I think I did both just for good measure so I won't end up with gasoline dripping out of that line.
with the TJ line is way better, it also has the damper on the rail which helps with the pressure bouncing when injectors are cycling - that's the best way to go if you want an external FPR.

Would this FPR work? Looks like it goes in line. Could take some modifying with hard plastic jeep lines. Also, what to do with the one on the rail? Looking to do the #19lb injector upgrade.
http://www.ebay.com/itm/UNIVERSAL-JDM-BLUE-ADJUSTABLE-FUEL-PRESSURE-REGULATOR-FPR-WITH-PSI-GAUGE-/281548001947

those are crap, for something as important as the FPR I recommend you use something proven, I chose Mallory for the price which if you plan it carefully is probably going to cost you $100 to $120 tops with all the fittings. I went bezerk on it and used all Russel AN fittings and adapters and SS braided line, there are cheaper ways to achieve the same but I wouldn't cut cost at the FPR. You can remove the hard plastic lines off the quick disconnect couplings and use rubber fuel lines with clamps to mate with the rail/lines.

there should be a lot of detail in the writeup Jeffy has mentioned.

[jmo69]

Thank you!