Results 1 to 9 of 9

Thread: 1JZ MX73 Auto problem

  1. #1
    Junior Member Grease Monkey
    Join Date
    Apr 2011
    Location
    Western Australia
    Posts
    164

    Default 1JZ MX73 Auto problem

    Hi Guys,

    I have just completed my "ultra sleeper" spec MX73 1JZ conversion

    Now I am having a problem with the auto.
    when i first drove it, it stayed in 1st until i let go of the accelerator, then would shift into neutral and free rev, untill i slowed right down and it would go back into gear.

    I instantly thought it was the solenoids, so i unplugged them from the box, and sure enough L=1st 2=3rd and D=OD, so that told me i was right.
    Then yesterday i finally decided to change them, and hey presto, worked like a charm, drove around for about 30 min perfectly fine.

    Then about 2 hrs later i went to go for a drive to a mates house, and same thing! holds 1st untill i release the pedal, then shifts into nothing.
    I get no ECU error codes and the o/d light isnt flashing, i have tripple checked my wiring, i have not tried another ECU yet.

    Now the other interesting thing is this engine was pulled out of a driving car (i drove it the day it was removed) and it drove perfectly finer and had no issues at all. the only electrical part that has been changed is the ecu (cant find the one that came with the engine)

    so im asking, is it possible for the ecu to shift the auto into neutral while the slector is in "D"? or is the problem in the transmission itself?

    any help would be great.

    Thanks, Haydn.

  2. #2
    Junior Member Automotive Encyclopaedia
    Join Date
    Nov 2011
    Location
    qld
    Posts
    1,123

    Default Re: 1JZ MX73 Auto problem

    just by an mv shift unit much cheaper

  3. #3
    Junior Member Grease Monkey
    Join Date
    Apr 2011
    Location
    Western Australia
    Posts
    164

    Default Re: 1JZ MX73 Auto problem

    Quote Originally Posted by dumbass View Post
    just by an mv shift unit much cheaper
    Thats not the info i was asking for.

  4. #4
    Junior Member Grease Monkey
    Join Date
    Apr 2011
    Location
    Western Australia
    Posts
    164

    Default Re: 1JZ MX73 Auto problem

    Oh forgot to mention, its a Twin turbo 1JZ-GTE from a JZX90.

  5. #5
    Junior Member Grease Monkey
    Join Date
    Apr 2011
    Location
    Western Australia
    Posts
    164

    Default Re: 1JZ MX73 Auto problem

    all good now. turned out to be the cluster not sending a good speed signal.

  6. #6
    Forum Member 1st year Apprentice
    Join Date
    Nov 2011
    Location
    South Australia
    Posts
    12

    Default Re: 1JZ MX73 Auto problem

    Hey mate, know this is an old post but
    What wires go where for the solenoids? Having trouble getting the trans solenoid unlocked

  7. #7
    Junior Member Grease Monkey
    Join Date
    Apr 2011
    Location
    Western Australia
    Posts
    164

    Default Re: 1JZ MX73 Auto problem

    3 pin plug near the back of the trans, they all go to the ecu (pins S1, S2 and S3)

    to test, supply them with 12v, the are internally grounded. more than likely you have a bad solenoid if it's "sticking"

    i sure have learnt a lot since this post!

  8. #8
    Forum Member 1st year Apprentice
    Join Date
    Nov 2011
    Location
    South Australia
    Posts
    12

    Default Re: 1JZ MX73 Auto problem

    Cheers mate I’ll have a look!

    Do you know if the four wires from the auto shifter have to be wired into the loom anywhere to make it work? Feels as if it’s not selecting gears

  9. #9
    Junior Member Grease Monkey
    Join Date
    Apr 2011
    Location
    Western Australia
    Posts
    164

    Default Re: 1JZ MX73 Auto problem

    not from the shifter in the car itself, but there is a selector switch attached to the gearbox. it's has 3 functions, neutral start lockout, position display for dash (and reverse lights) and also tells the ecu when you put it in L or 2 so the ecu will hold those gears.

    it's probably not your issue though, the auto will drive normally without it.

Similar Threads

  1. mx73 auto trans conversion ??
    By cressydan24 in forum Tech and Conversions
    Replies: 17
    Last Post: 17-12-2011, 04:00 PM

Bookmarks

Posting Permissions

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