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

  1. #31
    Senior Member
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    Quote Originally Posted by alexdmc1 View Post
    This Is my replacement unit. Attachment 70639

    Inviato dal mio Redmi Note 8T utilizzando Tapatalk
    Well, it is malfunctioning. Maybe send it back for repair or replacement? Maybe there is some kind of warranty?
    David Teitelbaum

  2. #32
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    I should have a guarantee. I wanted to remind you that when you move the lever to second gear manually it works perfectly. shifting from: 1-2 and 2-3 works perfectly. the downshift from 2-1 also works both cold and hot... if it were a computer problem it shouldn't always do it... in my case only the 3-2 shift without accelerating stops working.... the problem arises when I don't use the pedal. the downshift from 3-2 by pressing the pedal works perfectly.....

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  3. #33
    Administrator Ron's Avatar
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    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
    I'm assuming that, after "the lamps are both off and the problems begin", the lights remain OFF while it coasts along for a bit of time acting up?? If so, I would try repeating the test and pulling fuse #13 when it starts the problems....If it does not settle down then and stay in third (assuming you still have high speed), I'd suspect something else since the solenoids should be disabled then (no shifting) and pulling the fuse should accomplish that....

    (I guess you know driving at low speeds w/o fuse#13 is hard on the lower gear clutch packs.)

  4. #34
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    Quote Originally Posted by Ron View Post
    I'm assuming that, after "the lamps are both off and the problems begin", the lights remain OFF while it coasts along for a bit of time acting up?? If so, I would try repeating the test and pulling fuse #13 when it starts the problems....If it does not settle down then and stay in third (assuming you still have high speed), I'd suspect something else since the solenoids should be disabled then (no shifting) and pulling the fuse should accomplish that....

    (I guess you know driving at low speeds w/o fuse#13 is hard on the lower gear clutch packs.)
    HI. I wasn't able to take the test you asked for. I find it very difficult to do this. I'm afraid of ruining the newly installed clutches. the problem only comes out when the car is warm, during the first kilometres, the car works perfectly, it seems strange to me that it is an electronic problem. because the gearbox works perfectly when you go from first to second and from second to third.... it makes me think that maybe it's a design problem. I hope other people with automatic transmissions are reading these posts too.....

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  5. #35
    Senior Member Bitsyncmaster's Avatar
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    Quote Originally Posted by alexdmc1 View Post
    HI. I wasn't able to take the test you asked for. I find it very difficult to do this. I'm afraid of ruining the newly installed clutches. the problem only comes out when the car is warm, during the first kilometres, the car works perfectly, it seems strange to me that it is an electronic problem. because the gearbox works perfectly when you go from first to second and from second to third.... it makes me think that maybe it's a design problem. I hope other people with automatic transmissions are reading these posts too.....

    Inviato dal mio Redmi Note 8T utilizzando Tapatalk
    Not saying it is electronics but, yes an IC or transistor can work fine cold and completely fail hot. Let it cool off and it will repeat the same.
    Dave M vin 03572
    http://dm-eng.weebly.com/

  6. #36
    Administrator Ron's Avatar
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    Quote Originally Posted by alexdmc1 View Post
    HI. I wasn't able to take the test you asked for. I find it very difficult to do this. I'm afraid of ruining the newly installed clutches.
    ...
    Inviato dal mio Redmi Note 8T utilizzando Tapatalk
    Remove the fuse and run two wires with male spade connectors to the fuse box. Connect them with a switch to make it easier.
    The test shouldn't bother the clutches since you would be performing the test at a medium to high MPH, no load (3rd gear). Just make sure you turn the switch back on before you try to pull off from a standstill (low MPH, load).
    Note that the GC calls for 3rd gear by turning off both solenoids -- Pulling Fuse #13 does the same thing. If there is no power, nothing else (such as a bad part, short, etc.) can turn the solenoid(s) on.

  7. #37
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    Hello all. after a few months of driving my DeLorean or some updates on the automatic transmission problem. I did a pressure test on the move I would like your opinion:

    Test 0: pressure line when hot temperature:

    113/108 psi to 2500 no vacuum advance/ third gear

    Test 1: pressure when cold

    Parking: 58 psi
    Neutral: 50 psi
    Retro: 50 psi
    Driver: 50 psi

    Test 2: pressure when hot

    Parking: 21 psi
    Neutral: 21 psi
    Retro: 21 psi
    Driver: 29 psi

    Test 3: cold temperature when changing Gear low gas:

    From 1 to 2: 159 psi to 87 psi
    From 2 to 3: 87 psi to 84 psi

    No pedal gas - 30 mph - 1000 rpm - 43 psi

    Test 4: hot temperature when changing Gear low gas:

    From 1 to 2: 130 psi to 94 psi
    From 2 to 3: 94 psi to 43 psi

    No pedal gas - 30 mph - 1000 rpm - 29 psi

    Test 5: vert hot temperature when changing Gear low gas:

    From 1 to 2: 100 psi to 72 psi
    From 2 to 3: 72 psi to 58 psi

    Test 5: Medium acceleration when hot temperature:

    From 1 to 2: 203 psi to 87 psi
    From 2 to 3: 87 psi to 58 psi

    the problem that occurs is a jolt when the car is hot and I release the accelerator at low speed:

    https://youtu.be/uRa4djWjs6Y?feature=shared

    thank you all




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  8. #38
    Smurfy Member axh174's Avatar
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    Quote Originally Posted by alexdmc1 View Post
    I wanted to remind you that when you move the lever to second gear manually it works perfectly. shifting from: 1-2 and 2-3 works perfectly. the downshift from 2-1 also works both cold and hot...
    Maybe I'm misinterpreting what you're saying, but with the lever in second gear manually, you shouldn't be shifting from 2 into 3 at all. You would go from 1 to 2 and no higher. In this gear, one of your solenoids should still be powered (if using the breakout lamp box, one light should be lit and the other should be off). So it's quite possible the issue affecting your transmission is related to the connections (such as the solder joints) for the remaining solenoid. Reflowing the solder joints, as David T suggests, could prove beneficial.
    1 + 1 = 3 for exceptionally large values of 1.

  9. #39
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    Quote Originally Posted by axh174 View Post
    Maybe I'm misinterpreting what you're saying, but with the lever in second gear manually, you shouldn't be shifting from 2 into 3 at all. You would go from 1 to 2 and no higher. In this gear, one of your solenoids should still be powered (if using the breakout lamp box, one light should be lit and the other should be off). So it's quite possible the issue affecting your transmission is related to the connections (such as the solder joints) for the remaining solenoid. Reflowing the solder joints, as David T suggests, could prove beneficial.
    you're right. i explained myself badly. forgive me.

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  10. #40
    Smurfy Member axh174's Avatar
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    Quote Originally Posted by alexdmc1 View Post
    you're right. i explained myself badly. forgive me.

    Inviato dal mio moto g54 5G utilizzando Tapatalk
    So, to summarize:

    1) When the transmission is cold, the transmission upshifts from 1st to 2nd to 3rd gear without any issues and at the correct times. It also downshifts from 3rd to 2nd to 1st with no issues and at the correct times.

    2) When the transmission is hot, the transmission upshifts from 1st to 2nd to 3rd gear without any issues and at the correct times *every time*. But the transmission will not downshift from 3rd gear to 2nd gear when your foot is off the gas pedal and the car is naturally slowing down. The transmission gets stuck in 3rd gear and the car starts to shudder. The same thing happens if you are applying a little pressure to the gas pedal, but not enough to prevent the car from slowing down and reaching the 3rd-to-2nd gear shift point.

    3) When the transmission is hot and the car is slowing down and it won't downshift from 3rd into 2nd gear, you can move the automatic transmission gear selector into 2nd and the car WILL then downshift into 2nd gear.

    Is this a correct summary? (Sorry for repeating all this, I want to make sure I clearly understand the situation).


    Assuming all of the above is correct, have you noticed any issues while the transmission is hot, in 3rd gear, and you are maintaining a 50mph cruising speed? For example, does the transmission ever slip?

    Do you experience any other type of strange shifting behavior? Does the transmission ever suddenly shift from 3rd gear down into 2nd gear when you are doing 60mph? Does the transmission ever try to upshift from 2nd into 3rd when you are doing only 35mph?
    1 + 1 = 3 for exceptionally large values of 1.

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