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Thread: 05 gto auto problem

  1. #1
    Tuner in Training
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    Aug 2008
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    05 gto auto problem

    im having a problem with my built 4L65E. it was gone through shortly after my 402 went in. its not bullet proof, but its got a lot of upgrades in it.

    anyways, i got the car delievered to me recently, and i noticed that when i leave the car in OD, the car will fall out of gear in 1st, 2nd, or 3rd (just go to neutral) when i let off the gas. when i get back on the gas it goes up to the RPM it should. once it actually reaches 4th, it will engine brake instead of going into neutral. it will do the same thing in 3rd, fall out of 1st and 2nd if i let off the gas, but engine brake when it gets into 3rd. if i try manually shifting 1st and 2nd, it will hold either gear and engine brake if i let off the gas.

    if i have the gear selector in OD and doing about 50km/h (sorry, im in italy so its metric), its in 3rd gear at around 2K rpms. now, if i put it in D, it will grab (TCC lockup?) and go down closer to 1K rpms (1200 or 1300, somthing arounf there)

    i talked to vince @ flt, and he said to check the tune. he thinks there is something wrong with the TCC not applying, and believes the tune is the cause.

    i dont remember having this happen before i got the car back. i tried matching the tune that was in it a while ago, and it didnt help. only things still different is the shift speeds, which i guess i can try changing. the reason stuff was changed in the first place was the shop doing the work had the dealer reflash the PCM. there was a surging idle that couldnt be tuned out. they reflashed the PCM, and it went away

    what else can i change to make it go away?

  2. #2
    Tuner in Training
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    bump

  3. #3
    what is the stall speed of the converter?

    My own car with a 2800 converter almost drops to idle if i back off. Also, generally the TCC will unlock at 0% throttle for the brakes to work effectively.

    Chris...
    I count sheep in hex...

  4. #4
    Tuner in Training
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    its a 3200 stall

    i was just concerned cause i dont remember it happening before. the car has been down since dec getting the motor built, then it took 2 months to get to me over here. so its been 4 months since i drove it, and a month or so before that the trans was rebuilt.

  5. #5
    Advanced Tuner 69lt1bird's Avatar
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    Oct 2007
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    983
    My 3500 stall does that, it took some getting used to, always felt like it was slipping.
    Free HP Tuners Beginners Tuning Guide

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    Michigan Snowmobiler

    1969 Firebird: 11.67@114 [email protected] 1/8 1.70 60 ft. EPS cam 234/246 .602.606 114+3, 6.0 LQ4, L92 heads milled 10.5:1, Ported L76 intake, ported 90mm Holley TB, 100mm MAF, FIC Custom injectors, Hooker LT, PYPES dual exhaust with an X pipe, 4L65e with all of the good parts inside, FTI 4000 RPM Stall, 12 bolt with 3.73 gears. HP Tuner tuned by me

  6. #6
    Advanced Tuner
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    4L65Es don't have the Overrun clutch applied in 3rd, 2nd, or 1st if the selector is in OD. If the selector is in 3rd and you are in 3rd, the overrun clutch is applied and you have engine braking (doesn't feel like neutral anymore). This is completely normal. See chart below.

  7. #7
    Tuner in Training
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    cool, thanks for the info. i just wanted to make sure nothing was wrong with it