First time posting here because I'm out of ideas. I installed a twin turbo kit on my 2004 350Z (Early DE) and ran it with the stock fuel system for testing. Worked great but obviously it needed more fuel and the tune adjusted so i installed a full fuel return system setup with a 255lph pump, R35 injectors, and a cjm return correction kit. I adjusted the injector and fuel settings through uprev and fire it up. Starts fine, sounds good but smells like raw fuel and tons on black smoke. Idles at 10 AFR on both banks.

I worked on adjusting the tune and it was unresponsive, adjusting latency, reducing minimum pulsewidth and reducing the MAF table to almost zero. I installed stock injectors on a stock tune and stock fuel pressure and its still idling at 10 AFR. I tried another set of 650cc Bosch injectors and still didnt work, tried a different fuel regulator and same story. I took out the fuel basket and looked over all the o rings and grommets, everything is good. I tried a different MAF and no difference. Ive checked voltages everywhere and even went as far changing my ecu and flashing that with Uprev as well. Im getting spark across all cylinders and i can rev it, but even on decel it doesnt completely lean out like it should

Ive been chasing this for weeks now. Its absolutely washing out my oil with fuel. Car is not usable because the amount of fuel thats dumping into the oil and all the smoke from the exhaust. Im open to every and any suggestions because ive gone over everything i can think of. I even tried running my intake to atmosphere so it would Idle as if it was NA. SOS Send help

 

Have you made sure that the regulator is plumbed correctly? That would only partially explain it though. If you are getting fuel when the car is in decel fuel cut, then leaky injectors are the easiest explanation. Have you tested the injectors? Do you have a fuel pressure gauge on the rail?

 

Yes i routed the fuel feed to Tee right before the rails to feed them in parallel, and then they loop around and join in on each side of the regulator and returns out the bottom. There is a pressure gauge on it that does move with adjustment, but not on the actual rail. Its a stock rail with AN fittings welded. Just for curiosity sake i borrowed a friend's regulator with a working gauge and it matched what mine was doing so they are both working. I also have tried with and without the vac line so i know the diaphragms arent leaking fuel into the intake and theres no other place for fuel to leak in since its top feed as well.

I thought about leaky injectors as well, i got the R35 injectors used so I thought to go back to stock and see and same thing but those could have gotten dirty while they were removed so I bought brand new 650cc Bosch EV14 and still the same. I removed the upper manifold so i can watch the injectors fire into the heads while cranking and they dont look to be leaking and have a decent looking spray

 

Without seeing your setup, I'd say either something isn't installed correctly, or your regulator isn't working properly.

 

What would be the best way to share my setup? Maybe a google drive with everything? I have a lot documented from my setup after i redid everything on my several look overs so hopefully something will jump out. At this point i would lot to be called an idiot for over looking something.

As per the regulator i tried with two different working setups and got the same result

 

I am attaching a link to a google drive which shows the majority of my setup, especially fueling

https://drive.google.com/folderview?...l1O_HbVd8nXS-i

Last night i was trouble shooting some more through my tune, pulling back some fuel pressure so it was 3bar static and ~37 psi under vaccum and trying to reduce my latency and injector minimum values. I was able to get it around 14.7 idle but it sounded kind of rough.. when i adjust the maf curve to get it running smoothly it was running at 12.8 afr. Thankfully its not smoking like a steam engine at this but it does not smell right at 12.8 afr idle and it doesnt sound right at 14.5-15 afr idle

Now it is getting better and its seems to be responding more to addition and subtraction of fuel but my idle is staying around 1000 rpm with +/-100 rpm fluctuations and my my AFRs are dancing. The videos are posted in the link as well. Trying to be as thorough as I can. I reduced my K multiplier and did work into the MAF curve but it still wont hit my targets, when I go to 0 psi transition i was leaning out at 15 AFR when it should have been in the 12s. I can probably compensate this all with my MAF curve but im more so trying to make sure it stops flooding itself at idle. I dont want to continue tuning more cells until idling and fuel washout are correcting.

Unsure if its all tune related causing my injectors not to respond as intended or something mechanical, but ive gone over the mechanical components several times. Open to suggestions

 

Talk to a tuner that is familiar with the injectors you plan to use.