Adding in line fuel pressure regulator
 

I know there are those of you that has added in line fuel pressure regulators and even installed/created a return system.
I'd like to know more about adding an inline adjustable regulator.
I would think that the oem would have to be disengaged??
Also I know there are many questions to be asked, so many configurations and reasons for doing so with variable different mods to indevidual setups.

For me in particular;
13 BRZ AT. Jackson W/high boost pulley, DW700 ports, DW300lpm pump. Delicious flex Fule Kit : and runs/maps from them.
Every thing has been working very well for the last 10k. A month ago it had an issue while running E85. (71%) After running through 3/4 tank. I turned on the Sport mode, and off the traction control. Getting on the petal caused it to fall flat surge lunge and seem like it wasn't getting fuel.
Promptly I ran a log with a local tuner, finding nothing out of the ordinary. As I drove off (same E85) the symptom rescuered
So before returning I stoped and toped off with more E85, after that it did not reacure. A month goes on and I filled up from the same vendor with the e85. (64%). Five mile and shit got sour!!! When I got home I noticed the light on the Delicious FF unit had whent out... Unplugging the box, drawing all but 3gal out and refueling with 91 oct It is hard to start if it wants to start at all.. Can not idel on its own, 16% petal to keep running, RPMs hop (stays be 1200&2800) no CEL, Fule seams to be flowing strong. This is were I am.
I have no Fuel pressure tester so..

My query is ; could this be the fuel pressure regulator? And if so can a in line be added with out removing the one in the tank?
Any suggestion...

Thanks

Have you contacted Delicious Tuning about it? Sounds worst than Fuel Pressure issue

Yeah Zach and I have been back and forth communicating about it..
I have a couple things to try at my disposal.. The list: Delicious unit replaced, arrives today, bad gas, spark plugs,( arrived today) clogged injectors?, and we have a hard drive full of tunes and maps (flex fuel, 91 straight, e10, e30, e60, e80 and base OEMs.) so that's all been tried or is in the works..
The regulator is where I'm not keen on being able to have the OEM still in when also putting in inline.?

Every day is one more day to learn something new and remember something old.

I ran 525whp on e85 with stock fuel system with 1000cc injectors and 485 pump. I don't think your regulator or non-return system is the problem

My guess is pump installation issue, broken or leaking o ring bleeding off volume, or its just failing all together

To answer your first question, no... unless you want lower pressure than what the in tank regulator is set to.

If you want higher pressure than the in tank regulator you'd need to totally remove it.

I'd agree that's not likely your issue though.

^Agreed. Adding a regulator will certainly not fix the issue i would look at the fuel pump and make sure it was installed correctly.

I had same issue and my car would also lean out, we would add fuel and then after a while it would lean out again. The issue was a oring leaking on the pump. What pump do you have and how many orings did you use?

Thank you for the answer on the doubling up on the FPRs. That's kinda what I thought but in the event that the FPR in the tank HAD failed, the second one in line, with pressure gauge would be there to maintain pressure and be a monitor.
The Fule pump I have is a DW300lpm orings. 3 it has Been great until the E from this particular vendor., but also when the symptom first showed up a month ago only under huge demand, and functioned fine (other vender e85 and pump91) under the same huge demand Leeds me to the bad gas.
So ...
I'm heading to work on it now I will post my findings..

Ok so... Installed the replacement Delicious unit (black box, reconnected, checked over and over.. Tried to start and same symptoms.. Won't idle on its own, only with a small petal pressure and hops around befween 1200-2800
So
Pulled the Fule pump.. Looking every thing over as it comes out.. All good and then replace the DW300 with the OEM.. All back in.. Purged the line 13 times.. Really never heard the oem pump ( seat and metal derby off) wouldn't even fire off...
So for peace of mind... I cyphon out 5 gal and add 3 gallon of new 91.. Purge the lines (1/2 gal). Replace the DW300 new orings and tight fit in the pump harnes. Replaced, primed 13 times started up still same symptoms.. Piped off lines on both sides of the anylizer and purged lines.. One then the other side.. It's flowing...
For shits and giggles i put in another omnie 3bar MAP sensor.. Turned it over , started but same symptoms. It won't idel, hops when petal held at 1200-2800 and RPMs clime but fall out some at higher RPMs. Pops and studders lower than 1200..
Driving me nuts...

I have new plugs to go in regardless..
I planed to see if I could get a Fule pressure gage to see for certain (58psi t the rails right????).

I had thought that by putting the Delicious unit back on things would have cleared up.. But no. I just can't seem to get it ..

Finally got it
Turns out that everything was right on the mechanical side..
I reflashed with my 3bar:flex fuel:highboost tune ( had done it twice in this process) going back it seams that the voltage for the 3bar MAP scailing was not taking.
Don't know why... But all in all flawless idle logs are looking AWSOME seeing 14psi boost, AFR. (930rpm idle) 14.3 +-, rail pressure 3-4 psi at idle
I'm liking it..
Thanks for everyone in put
There is not much out there regarding these symptoms.

Can you or Delicious expand on the statement I quoted in bold... to help us understand the problem and solution.

Well looking back... What seemed to be happening during the reflash was that, for some reason the ECU just didn't want to belive there was a 3bar MAP. It seemed to want to "read" what the oem MAP would have been sending aka ; the voltage wasn't being recived properly...
All in all it corrected itself after doing the reflash a second time.

Some ECUTek bug? Or you changed the tune you were flashing?

No, did not Sean to be the Ecuteck. The symptom first started with E85 from a particular station, the engine behaved odd after 3/4 tank of it. Then a month latter ( after running three other tanks from a diff station of e85 with no hiccups) a return to the "first" stationE85 the hiccups started and progressively got worse...
At which point I discovered the Delicious Flex anylizer light was not lit...
Upon sending the unit in to Delicious for inspection and replacement.. Then reinstalling it, the hiccups ( eradic ideling) continued.. After all the checking and rechecking and flushing the fuel lines, tank etc.. I did a reflash from the original "email" tune from Delicious.. It started and has been running fine since...
Now. Going back to my logs and comparing them, I saw that during the episodes (eradic ideling). That the MAP voltage had dropped back to what OEM (1bar) was
Apparently the ECU was trying to adjust for the reading it was getting from the O2/Flex fuel anylizer that wasn't functioning (stoped working) and did only what it knew to do....
Delicious has pulled the unit apart but cannot see why this had happen nor has had an issue of its like...
My guess and its only a guess is that the E85 from that station had something to do with it...

All in all the MAP scaling was not reading right due to the anylizer failure.. What caused that is a mystery....
The guys at Delicious have been unbelievably helpful and have always had the best customer service I have encountered over the years.... Thank you Zach and Bill!!!


So are you haveing some issues?