Fuel cut fix

Discussion in 'N/A Mods & Tuning' started by 2008 Toyota xrunner, Jun 26, 2018.

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  1. 2008 Toyota xrunner

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    Hey guys.
    Looking to see if anyone else had this problem before. I’ll just keep it simple and not a whole story lol
    Filled up my tank and drove the truck for a few days. Half tank comes and I start to punch it and my afr gauge goes to 10 and the ucon fuel cut kicks on and I get a check engine light. No codes to be read. So I top off the tank and I punch it again and it drives perfect afr is at 12 at wot.
    Could this be a fuel pump problem?

    Thanks ahead of time guys.
     
  2. SoFloBlue

    SoFloBlue Member

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    Never had that problem, had something similar with a heavy rain and standing water on the ground getting splashed up. The check engine light was on and still no code ?
     
  3. 2008 Toyota xrunner

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    Thanks bro. So I just drove it again and clear dry day and the code pops up again and it says my bank 1 sensor 1 has low power. So I’m gonna see what I can do to fix this code.
     
  4. BSP06XRU

    BSP06XRU Old Member

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    Are you lowered? Might want to check your charcoal canister for cracks.
     
  5. NHXRUNNER

    NHXRUNNER "New Hampster"
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    12 is pretty lean for WOT. The symptoms seem opposite of what I'd expect with a fuel pump problem. At 10 AFR you're getting more fuel. The only issue I've seen with the fuel pump upgrade before is the hose cracking due to improper installation. This causes a lean condition once the fuel level drops below the level of the crack. Typically starts as a hard start.
     
    x-runner kid likes this.
  6. 2008 Toyota xrunner

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    Sorry I never heard of that rookie here lol
     
  7. 2008 Toyota xrunner

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    Well I do not have a fuel pump upgrade yet I’m still on the stock fuel system and I have about 160000 miles on the truck. I’m wondering if that could be a problem and maybe I just change the fuel pump and filter already. But I also get a p2238 code and I can’t figure out if it’s coming from me installing the ucon. It only happened after I got the ucon installed
     
  8. XMPLRY808

    XMPLRY808 Active Member

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    For this being under a NA topic assuming he doesn’t have boost. 12 afr isn’t “pretty lean” at all. Every motor is different but I’m pretty familiar with tuning 1grfe motors, with boost and all motor. 10 afr is too rich even with boost.
     
    #8 XMPLRY808, Jun 28, 2018
    Last edited: Jun 29, 2018
  9. 2008 Toyota xrunner

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    Yea I’m not boosted. And my afr sensor is throwing it off and making me 10 at WOT. hope I can fix it tonight
     
  10. NHXRUNNER

    NHXRUNNER "New Hampster"
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    LOL, admin not reading the section! Now that I'm boosted that's all I think about. 11.1 is the goal for me. I wasn't saying 10 was good. Like you said, that's rich boosted, nevermind N/A.
     
  11. shane881510

    shane881510 Active Member

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    Everytime I had the p2238 code it’s either bad sensor or the ucon just thinks it is. Unplug and plug back in the oem plugin on the Ecu. Don’t undo the plugs that come off ucon into the oem ecu. Just the the oem plugs that’s pushed into the ucon. They wiggle and get loose. I have to do it once a month on my ucon because of a throttle control code and afr sensors code.
     
  12. 2008 Toyota xrunner

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    So update on this situation and I changed out the pig tail extension and comes out that the connection was getting loose so I bought another one and it works fine now. Thanks everyone for there help
     
    NHXRUNNER likes this.
  13. NHXRUNNER

    NHXRUNNER "New Hampster"
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    Good to hear you’re up and running
     

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