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Thread: 99 Truck 5.3 cam & heads Goes super lean in gear

  1. #1
    Advanced Tuner uarperformance's Avatar
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    99 Truck 5.3 cam & heads Goes super lean in gear

    Having a brick wall. As soon as I put this truck in gear it will start to crank full lean and will not add fuel, sits at 17.5 AFR If I just take it off the Closed position it will go back to taking away fuel because I have it pretty rich to get a response. What am I missing? Mass air flow has been removed. Came in from another tuner And had many issues from map senor connections to bad cam sensor. Had to be towed in because it wouldn't stay running.
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    Last edited by uarperformance; 02-26-2015 at 05:54 PM.

  2. #2
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    What cam is it? You sure your map sensor connector is fixed? Can you post your tune using 2.24 instead of 2.25?

  3. #3
    Advanced Tuner uarperformance's Avatar
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    Customer Doesn't know. Some one else built the motor. I will try. Map sensor vacuum was split off a vacuum log going to the valve cover originally. Lol. KPA 101 at turn of key. the thing will go lean AT 50 TO 60 kpa WITH NO LOAD and fat as a pig at 70 to 75 KPA and I don't see it in the tune.
    Last edited by uarperformance; 02-26-2015 at 08:32 PM.

  4. #4
    Advanced Tuner uarperformance's Avatar
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    see if this works

  5. #5
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    Injector data does not appear to be correct, without knowing what injectors cant help you, but if stock fpr is still on should be same value all the way. Set maf high rpm disable to max value. And closed loop is disabled.
    Last edited by mecanicman; 02-26-2015 at 10:25 PM.