Turbo 2018 Tundra - Lean Issue

I have a 2018 Flex Fuel Tundra, turbocharged. I am having an issue with it going really lean at high load/rpm. I got a video of the fuel pressure, and it looks like that is our issue. It fluctuates and falls quite a bit. I have a local tuner that tunes all toyota models, and has done many SC Tundra's without issue. So my tune is good in terms of that. He tells me injectors are commanding high pw in the datalog, but it goes lean.

The fuel system has been modified by another shop and it sits as follows:
-The pump is jumped to the 12v feed that comes to the fuel pump controller
- the pump looks to be a hellcat pump
-in the sending unit, it was bypassed from the donut, and runs directly to the feed out of the sending unit
- looks like holes where cut on the cannister to allow fuel to go in
- the pump feeds straight to the ffv valve
- the return port of the ffv valve was blocked off with a bolt
- the return to tank of the ffv valve on the sending unit was blocked off as well with a bolt
- the fuel the flows out of the ffv valve to the rail as oem
-on the return on the other bank's rail it is converted to -6 an
-goes to a boost referenced fuel pressure regulator (set to around 58psi)
- the retrun on the fpr then adapts back to the oem hard line firewall
-then returns as oem to the fuel sending unit on the port that is un-regulated, to tank atmosphere

I have been messing around with the relay that controls the FFV valve. When I activate it, I notice the tone of the pump changes. And the truck runs about the same both ways. My thing is, if it is blocked off, when I activate it, it should block flow. But the truck runs both ways.

Ultimately, I think the fuel feed line running through the ffv valve, which is operating questionably, might be causing a restriction. Especially since I've seen 4firemandans build, he bypasses the ffv valve with the non ffv lines and prospeed sells fuel lines that eliminate that all together.

The injectors are the tan oem looking ones, and the look like they where scribed with numbers. Maybe modified? If I can get the fuel pressure problem fixed, we will be doing injectors.

Do you all have any ideas?

 

This is the setup

 

Got pictures? I run a turbo on my flex fuel and all I did was jumper the relay in the fuse box to make the valve close and bump the pressure up.

What boost are you running?

There is a limit as to how much stock injectors and pump can flow. I’m running upgraded 650cc injectors with stock pump and around 6.5-7psi I’m starting to run out of fuel.

 

these are the injectors

boost around 5-6 lbs

 

Got any logs you can share?

 

https://www.tundras.com/threads/turbo-charging-a-tundra.115951/unread

Try this^^^

all sorts of info in here

 

5-6 psi and you're out of injector. If I recall correctly, I was running out of stock injector flow around 3.5psi and had to set the tune to throttle back above 5k rpm because of injector.dutt cycles.

As @centex has proven, jumper the FFV fuel pump for high pressure mode, run some 650s, and you're good your current oost levels.

There are also ways to get rid of the FFV portion of the system and run a traditional fueling system. You can search for that on this forum. I believe it was @e30cabrio who cracked that nut.

Regardless 5-6psi is a fun but still conservative place to be, so hopefully it is just injectors. The logs can help you find your DC to confirm. That up pipe and mounting location looks familiar. Whee are you located and how did you run your plumbing to the intercooler. I like the air filter being further away from everything, too. Mine is straight off the nose of the turbo with a small spacer to keep the filter flange from melting. Also curious if the fuse block is boxed in or if that is just a wrap.

Oh!! And welcome

 

Fuseblock has a metal shield wrap around

We are in Orlando FL

Intercooler goes in and out around the passenger headlight

gonna see if i can find e30cabrio build so i can order the non ffv fuel line.

what cc are the oem injectors? and have you ever seen modified ones?

 

I’ve read the flex fuels are in the 530cc range. I haven’t read of anyone modifying the factory injectors.

 

You should read this first post in the SC thread. It has a ton of useful information that is not just for SC, but for all FI setups.

Injectors, duty cycles, and the helpful links at the very bottom will get you down the path.

https://www.tundras.com/threads/general-supercharger-thread.85513/#post-2155383

 

I read through the general supercharger thread. Will be reading through the turbo one posted.

I went ahead and eliminated the ffv valve. if anyone is wondering the following filter is an adapter for the 3/8" line from the pump to 5/16" hose going to the hardlines in front of the tank.
https://shop.advanceautoparts.com/p...-16-outlet-metal-fuel-filter-86316/10842039-P

The pressure seems more stable but still riding lean at high load. My tuner is coming in tmrw to go through, will follow up with more info.

FYI i put a camera in the engine bay, and noted that fuel press was droppin

 

I'm curious to hear what you find. Buried in the SC thread, there was discussion about which pumps worked best and if drilling holes and such worked as intended, and I believe the end result was "no" and people run with whatever fits without modification. They're a welcoming group over there so if you post up, I'm sure they'll respond. They tolerate us TC guy well and this appears to be a FI fueling issue.

One of the simple questions we haven't asked yet is about fuel levels in the tank. Is it over 1/2 a tank?

 

i read about the fuel level issue. so i made sure to have over 1/2 tank of fuel

 

What’s your maf voltage at? Wonder if it’s also tapping out early.

 

MAF voltage is a great question.

Speaking of electrical, is the 525 wired for up to 25amps of draw? That's a lot of pump.

 

@kingsperformance I read to stay away from the walbro hellcat fuel pump as it can be unreliable and go with the walbro 450 model 267 drops in the ffv canister. Same for the Deatschwerk dw300 pump. No need for holes and you can do the 4fireman dan mod. The ffv canister venturi will keep up with keeping it full. Only reason people drilled holes in the non ffv canister is the venturi wouldn't fill it up when running a larger fuel pump.
Ffv injectors are 485cc and green trd are 535cc. Is the supply hose from pump to canister slipping off. Use quality fuel line with fuel injector clamp. I'd look at the hose setup.