So i have a fuel issue where upon tuning i am leaning out at above 5000rpm despite FPR holding at 60psi, it starts at 40 -50 and goes to 62 then drops back to 60.

Was working fine until
1. AAM Fuel rails corroded from E85 and sprayed fuel from one of the rails leaving white powder substances around the seats of the rails and in injectors.
2. I had to take out fuel basket and replace return line o-rings as fuel was leaking and then they were sealed around the fitting

My fuel setup
https://my350z.com/forum/forced-indu...x-haltech.html

Basically
- Walbro 485
-8AN supply
-6AN intank and return
-A1000 FPR
-CJM Rails with dapeners
-Haltech E-flex and ECU
- DW 1000cc

I went to take off the fuel return line to see why it was leaning out and i noticed along with the usual fuel leaking out of the line it was also leaking out of the return port on the actual basket??? The tank was massively pressurized and as i undid the screws a massive woosh of air came out.

Only other thing i did was plastic weld around the return port bulkhead washer so it wouldnt leak anymore as well as replace the o-rings under the washer to e85 ones.

Any ideas what is going on ?
Is there a bleed line somewhere that is not opening up due to E85 swelling the seal or something and vapours being trapped in?

I notice my FPR is staying at 40-50 and wont go down when car is off.

 

What power level? With e85 and 1000cc injectors you will need a higher base pressure. I had to move mine up to 60psi base just to keep injector flow high enough. I would log the injector duty cycle and injector pulse width. I would bet that they are maxed. If the base pressure at 40 and you are seeing 62psi then I'm guessing you are about 22 psi of boost.

Now, when you raise base fuel pressure it will run the walbro out I fuel sooner so I would watch fuel pressure and if it starts dropping up in high rpms then you are out of pump. With dual walbro I have 510lpm. The walbro 485 is actually a walbro 400 and flows 400 lpm so for high hp it will probably run out.

Not sure why you are getting corrosion and oring problems. I've been on e85 for years with Cjm setup and no problems with corrosion or orings.

The tank pressure sounds like the gas cap relief valve is clogged and failing. If fuel isn't coming out the gas cap it's probably a negative pressure sound you are hearing which could also starve fuel. Loosen be gas cap and do a pull and see.

 

If you had some orings damaged I would check anything in the return for pieces that could clog it. Some fprs do hold pressure for a few minutes after the car is shut down. My old one did but my new one drops as soon as the car is off. It will vary based on line pressure and apron pressure in the fpr. After it sits about 10 mins check to see if pressure has bled off. If so then it's normal.

 

ok car was 11psi at 460hp, upon doing a run before tuner changed anything it was 6psi and 360HP or something like that.. so we are nto even getting what we got before.. 420HP and 11psi on pump fuel and 460hp and 11psi on e85.

we took the fuel cap off and blew into it, nothing, sucked it and air was let in.

Tuner took the fuel cap off and did a run, same issues.

 

o-rings for the return bulk head where leaking , always did so i got e85 compatible ones, when swapping them out the one inside the basket was torn.

It takes about 45mins to 1 hour to drop back to 0, but this was ages ago i checked and not rescently. my basket is out so ill have to put it back in to check. so to see if anything is in the return line i take the basket return line off and blow through it and then check the AAM fuel regulator replacement part ? I have a another oem fuel basket which i will modify and use as they current one is damaged from removing it, the output plastic port snapped off when i was taking the -8an off..

 

I am also getting help from Charles from CJM (huge thanks to him for answering on the weekend !!! great guy). between u and him i have the gurus helping !!

here was one of his responces
"The pressure and the leaning out are probably unrelated since your fuel pressure in the rail is normal, whatever other problems you have with the fuel system will be unrelated to it going lean" and "Pressure in the tank would be from the evap system not doing it's job or your setup creating more evaporation than the evap system can handle, or your evap solenoid just hadn't had a chance to open before you opened the tank."

and my thoughts

Ok so starting to make sense, when i try and blow air into the outlet port of the tank i canT push air in so this is testing the check valve ?
Yeah my FPR takes about an hour to go to 0.

So going leaning is not related to my EVAP issue/ pressurized tank which means get injectors flow tested?

I just read HKS use a one way check valve on the EVAP system vacum line for the supercharger kit but i never got one with my HKS ST kit... "There has to be a reason why HKS has one installed on the 350Z's EVAP line to stop boost from entering the EVAP purge tank and valve. The system is not made to have air pushing the wrong way through it. I would recommend installing one on there" - So for some reason my boost is going into the EVAP line, why is this happening to me and not others
where do i put this one way check valve ? = check link below

so maybe i didnt give it enough time before car was off and me opening the basket but when i take the EVAP solenoid off from under the tank is there a way to check it? How and when does the EVAP solenoid work ?

 

Found this
http://www.superstreetonline.com/tec.../photo_20.html

If the Solenoid did leak during boost would this stop it ?

and pics of the EVAP purge valve near fuel tank and the charcoal canister
http://www.nissanpathfinders.net/for...er-and-valves/

 

Aswell as testing the EVAP solenoid, The EVAP purge valve in tank and the charcoal canister and doing the check valves on EVAP, Brake Booster and Pre turbo pipe that should deal with my issue ??

Would boost leaking into EVAP system mean i cant make boost ?

I made a diagram based on help given so want some feedback if it will work and if the yellow line is needed. i guess only for those on boost alot with no break like track.

 

Ok i tested the EVAP solenoid and i could blow through both ports and suck also. so its letting air straight through from the plenum into the gas tank.... even after leaving engine running for 100seconds which is when it starts pulsing it did not make a difference.. But could that cause boost leak / Leaning out issues or just the pressurized tank ?

 

It would pressurize the tank. Some evap solenoids do go back and won't hold boost. I know some ppl on here say that you have to have that check valve in place like in your diagram but I pressure tested my evap solenoid and it held 50psi without leaking so it's definitely not a design flaw, it's just a part failure. Putting a check valve between the evap and the plenum so it stops boost from going into the evap system should fix the issue instead of having to replace the solenoid. Don't hook up any other crazy systems like you put in there to draw out of the tank. During boost times you won't build up any significant pressure in the tank so when you let off the throttle and the plenum returns to vacuum it will pull the pressure off the tank like it was designed.

So that will fix your issue on that front. Did you check injector duty cycle? The fuel pressure and injector size you are running would easily max out at those power levels and cause it to go lean. I'm running 20psi higher base pressure than you just to get enough fuel through the 1000cc injectors on e85.