FRAMING JOHN DELOREAN - ON VOD www.framingjohndeloreanfilm.com
Page 3 of 4 FirstFirst 1 2 3 4 LastLast
Results 21 to 30 of 36

Thread: Transmission jerk on downshift 3nd to 2nd low Speed no pedal gas

  1. #21
    TNDMC Founder JBaker4981's Avatar
    Join Date:  May 2011

    Location:  Cookeville, TN

    Posts:    342

    My VIN:    628

    Club(s):   (SEDOC) (DCUK)

    Quote Originally Posted by alexdmc1 View Post
    Attached. Acceleration 2-3 upshift. Full Power.https://cloud.tapatalk.com/s/664f5552...224-WA0022.mp4

    Inviato dal mio Redmi Note 8T utilizzando Tapatalk

    I would not drive the car as briskly as that while diagnosing this - The car downshifted 3-2 for most of your video and then 2-3 at the very end.

    I would be interested to see how she accelerates in 3rd without hitting WOT (Wide Open Throttle) and making it down shift. I have a feeling that you are going to be slipping in 3rd at lower speeds or other behaviors may appear.
    Last edited by JBaker4981; 05-23-2024 at 10:54 AM.
    Jesse Baker
    VIN 628
    Black Interior, Automatic
    TNDMC: TN DeLorean Motor Club

  2. #22
    Member
    Join Date:  Aug 2022

    Posts:    81

    Quote Originally Posted by JBaker4981 View Post
    I would not drive the car as briskly as that while diagnosing this - The car downshifted 3-2 for most of your video and then 2-3 at the very end.

    I would be interested to see how she accelerates in 3rd without hitting WOT (Wide Open Throttle) and making it down shift. I have a feeling that you are going to be slipping in 3rd at lower speeds or other behaviors may appear.
    Hi JBaker. I just returned from a long tour. when cold it drives well, when hot the problems begin.....if I drove at full throttle in third gear no problems, no slipping. I also replaced the ATF dexron 3 oil to be safe but the problem was not resolved. I notice that when I release the accelerator, in third gear the revs (rpm) are low? it's like it doesn't have enough pressure to tighten the clutches....I don't know. what do you say?https://cloud.tapatalk.com/s/6651f52b...525-WA0022.mp4

    Inviato dal mio Redmi Note 8T utilizzando Tapatalk

  3. #23
    Administrator Ron's Avatar
    Join Date:  Jun 2011

    Location:  North GA

    Posts:    6,190

    Club(s):   (SEDOC) (DCUK)

    Maybe I'm not following all this correctly but:

    Quote Originally Posted by alexdmc1 View Post
    I notice that when I release the accelerator, in third gear the revs (rpm) are low?
    Are you sure that isn't where you are in 2nd gear (accelerating) and when you let off it shifts up to 3rd (which would drop the RPM, i.e., normal)?

    Quote Originally Posted by alexdmc1 View Post
    it's like it doesn't have enough pressure to tighten the clutches...
    If the clutches aren't tight the engine would rev up a lot.

  4. #24
    Member
    Join Date:  Aug 2022

    Posts:    81

    Quote Originally Posted by Ron View Post
    Maybe I'm not following all this correctly but:

    Are you sure that isn't where you are in 2nd gear (accelerating) and when you let off it shifts up to 3rd (which would drop the RPM, i.e., normal)?


    If the clutches aren't tight the engine would rev up a lot.
    Hi Ron. How are you. you're right: during acceleration the car shifts from second to third and obviously the engine rpm drops. like every other car does. the problem is when I'm in third gear at low speed without accelerating (foot raised) instead of downshifting you hear jerking..... but when cold for the first 20 km everything works perfectly.

    Inviato dal mio Redmi Note 8T utilizzando Tapatalk

  5. #25
    Administrator Ron's Avatar
    Join Date:  Jun 2011

    Location:  North GA

    Posts:    6,190

    Club(s):   (SEDOC) (DCUK)

    Quote Originally Posted by alexdmc1 View Post
    Hi Ron. How are you. you're right: during acceleration the car shifts from second to third and obviously the engine rpm drops. like every other car does. the problem is when I'm in third gear at low speed without accelerating (foot raised) instead of downshifting you hear jerking..... but when cold for the first 20 km everything works perfectly.

    Inviato dal mio Redmi Note 8T utilizzando Tapatalk
    I see... My first guess would be the GC, new or not considering your other tests results. Put test lights on it if you haven't yet...

  6. #26
    Member
    Join Date:  Aug 2022

    Posts:    81

    Quote Originally Posted by Ron View Post
    I see... My first guess would be the GC, new or not considering your other tests results. Put test lights on it if you haven't yet...
    Hi Ron. I just did the test with the lights. At first everything works perfectly. the lights come on and the automatic transmission shifts correctly. when it warms up and in third gear at low speed I don't press the accelerator pedal, the car remains in third gear, the lamps are both off and the problems begin..... thanks for your help

    Inviato dal mio Redmi Note 8T utilizzando Tapatalk

  7. #27
    Senior Member Bitsyncmaster's Avatar
    Join Date:  May 2011

    Location:  Leonardtown, MD

    Posts:    9,042

    My VIN:    03572

    Quote Originally Posted by alexdmc1 View Post
    Hi Ron. I just did the test with the lights. At first everything works perfectly. the lights come on and the automatic transmission shifts correctly. when it warms up and in third gear at low speed I don't press the accelerator pedal, the car remains in third gear, the lamps are both off and the problems begin..... thanks for your help

    Inviato dal mio Redmi Note 8T utilizzando Tapatalk
    This does really sound like the electronics are failing in high temps. It's to consistent to be a marginal connection.
    Dave M vin 03572
    http://dm-eng.weebly.com/

  8. #28
    Senior Member
    Join Date:  May 2011

    Location:  Northern NJ

    Posts:    8,614

    My VIN:    10757 1st place Concourse 1998

    Quote Originally Posted by alexdmc1 View Post
    Hi Ron. I just did the test with the lights. At first everything works perfectly. the lights come on and the automatic transmission shifts correctly. when it warms up and in third gear at low speed I don't press the accelerator pedal, the car remains in third gear, the lamps are both off and the problems begin..... thanks for your help

    Inviato dal mio Redmi Note 8T utilizzando Tapatalk

    Go back to my post #5. You have bad solder joints on the circuit board. You just have to open it up to get to the circuit board and reflow some solder on each joint. Between the vibration and the temperature a cold solder joint can cause this, very typical. It is possible to do this without taking the whole thing off. You remove the cover, pull the circuit board out enough to get to the backside and with a soldering iron (a small pencil iron, you don't need a big gun) you reheat each joint and add a SMALL amount of fresh solder. Be careful not to add too much solder or make any solder "bridges" to other circuits on the board. On some of the shift computers you do have to remove the coating, use a small steel brush.
    David Teitelbaum

  9. #29
    Motors about after dark Michael's Avatar
    Join Date:  May 2011

    Posts:    4,819

    My VIN:    Banged your VIN'S mom

    Quote Originally Posted by David T View Post
    Go back to my post #5. You have bad solder joints on the circuit board. You just have to open it up to get to the circuit board and reflow some solder on each joint. Between the vibration and the temperature a cold solder joint can cause this, very typical. It is possible to do this without taking the whole thing off. You remove the cover, pull the circuit board out enough to get to the backside and with a soldering iron (a small pencil iron, you don't need a big gun) you reheat each joint and add a SMALL amount of fresh solder. Be careful not to add too much solder or make any solder "bridges" to other circuits on the board. On some of the shift computers you do have to remove the coating, use a small steel brush.
    He is using Ed's governor which I believe is a new solid state design like DMCH sells.

    dsc08364.jpg
    Last edited by Michael; 05-27-2024 at 12:24 AM.
    http://dmctalk.org/image.php?type=sigpic&userid=90&dateline=161808992  9

  10. #30
    Member
    Join Date:  Aug 2022

    Posts:    81

    Quote Originally Posted by Michael View Post
    He is using Ed's governor which I believe is a new solid state design like DMCH sells.

    dsc08364.jpg
    This Is my replacement unit. IMG_20240527_081500.jpg

    Inviato dal mio Redmi Note 8T utilizzando Tapatalk

Page 3 of 4 FirstFirst 1 2 3 4 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •