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Thread: 1-2 Shift Flare over half throttle...B@STARD Setup!

  1. #1
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    Default 1-2 Shift Flare over half throttle...B@STARD Setup!

    Hi guys,
    Trying to get my shift times down to a reasonable level. My 1-2 shift time is a couple of seconds at like half throttle. So far I've removed T/M (didn't help) and lowered the shift times to .1 across the board. This didn't help either. I have left the pressure stock for now.
    I realize my transmission can shift from 1-2 VERY quickly as in SD tune it will literally rip your head off and I mean BAD! So I think I'm missing something because as soon as I reflash engine ECU back to utilize the air mass my shifts go very slow again. I feel I will ruin the transmission if left alone. The problem feels like the transmission slips a bit during the 1-2 shift and then finally grabs. The 1-2 shift is so slow that the engine hits the rev limiter even though I have part and full throttle shift points lowered dramatically (below 5200).
    This is a bastard setup. LH6 engine 2006 with LH6 E40 O.S. Tranny is 4L-60 2004 Sierra 2wd with a GTO T42 O.S. the reason I used the GTO O.S. is because my transmission does not have an input shaft speed sensor like all LH-6 4L-60s have. And with that O.S.(from the LH6) I kept getting a missing hall sender code from the T42.
    Engine/Trans are in a Volvo and has no big power improvments besides headers and decent air filter setup. Stock cam, around 350 hp. DOES NOT utilize an ABS computer out of a GM. I'm wondering if this is screwing me up. Have tried logging data with the T42 but can only log about 3 pids....even with a Snap-On scanner, not sure why. Even with the tranny controller from the LH6 my shifts were slow.
    Sorrry this is a bit long winded. I've had quite a few trannies apart and rebuilt a few with success. My tranny "tuning" experience is none. This is the first time I've tuned one (or tried) so I will proceed with caution.

    Thanks, John

  2. #2
    Joe (Moderator) joecar's Avatar
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    Sounds like the TRQENG calculated from airmass derived from MAF is too low...

    Possibly either your MAF is way dirty, or B5001 is way low, and/or shift adaption is working incorrectly.

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    Well certainly Joecar I appreciate the help. Again and again and again!

    My Maf is clean... like new. The whole engine package I bought only had 6 miles on it. I have another Maf to try off my wife's GTO (sorry honey).
    I really think it's a tuning problem that I need to learn. The funny thing is my VE table was off about 24% lean on in the lower RPMs when I first started tuning. So once I got the VE close(not perfect) I had to add about 20% to my Maf frequency B1098, B1099 as mine is an E40. So now my LTFTs are still lean about 8-10%. Suppose this could be the problem? Joecar when you say "way low" , how low do you mean?

    I've set ALL of my shift times to .100. Still really slow shifting.

    Since the shifting bangs HARD in MAF fail mode I'll assume my trans is not mechanically challenged (like me).


    Please reply on my next step and thanks again, John

  4. #4
    Joe (Moderator) joecar's Avatar
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    John,

    The PCM indexes the pressure tables using TRQENG which it calculates using the cylinder airmass derived from the VE and/or MAF...

    Being 20% below means that TRQENG will be 20% below, which means the PCM will lookup the wrong pressure.

    And (I don't know the inner details of this) shift adaption probably relies on the TRQENG as well as shift time.

    Also, when the MAF is failed, check for the MAF DTC's in the transmission diagbnostics tables E0101-E0104 and disable them.

    Cheers
    Joe

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    Thanks and I will check after the rain stops here. Rear tirers are SHOT. Bald 215s don't make for a good rainy day ride!


    John

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    That was the answer Joecar. My {B1098,B1099} were off quite a bit. I'm not able to find where to disable shift pressure in E40, T42 though. I'll just put up with hard shifts in SD mode for now.

    Thanks, John

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    Any outcome?

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    Like I had said earlier in the post I was using an O.S. from an 06 Envoy with DOD. My operating system for the T42 transmission controller was from an 05 GTO 4L65. No matter what I did I never got it perfect. In fact the Envoy tranny sports a hall sender for the input shaft, something the GTO transmission does not have. I suspect this has something to do with the DOD.

    As I progressed through last summer I ditched the DOD setup because the whole vehicle shook repulsively when the DOD engaged. I did not feel the extra gas mileage was worth it either.

    So once I switched to an operating system for both engine and transmission from an 06 GTO all those problems went away....except for the rear tires being bald. There's just NO way to keep good skins on the rear of this thing.

    Mix and match and you shall see, it won't work as it meant to be.

    John

  9. #9
    Joe (Moderator) joecar's Avatar
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    Quote Originally Posted by ssvolvo View Post
    ...There's just NO way to keep good skins on the rear of this thing...
    John,

    Maybe replace the shocks/dampers and springs, and all rubber bushings.

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