ECU repair for Nistune board install

  • #1

    ECU repair for Nistune board install

    Repair of another Z owners Nistune installation gone frightfully wrong.

    They guy who removed the Eprom obliterated every via and pad when removing the eprom. I had heard it's difficult job even with the right tools as these old boards are delicate. I loaned a spare ECU to the guy who owned the Z on the condition that he give me the other one to repair.

    Curious about installing Nistune myself, i didn't know what i was getting into but have decades now of soldering experience.*

    I ran new wire traces with solid 32awg wire strands, soldered them to and from traces that had been trimmed and bared and then potted them with a UV curable resin.

    untrimmed:
    ecu1.JPG

    trimmed, soldered and cured.
    ecu2.JPG

    topside socketed
    ecu3.JPG

    control ecu i socketed myself with the professional rework tools i have access to at my employer (i didn't want to completely trash the other guys work without doing it for myself)

    ecu4.JPG

    So i guess i can install Nistune boards now ? ‾\_(ツ)_/‾ Even milled out the pocket for the USB.

    * I'm going to X-ray the rework on Monday to see if that decades of experience missed anything.

    Finished product:

    ecu5.JPG


    84 AE/Shiro #683/Shiro #820/84 Turbo
  • #2
    Xray day

    88T ECU that had it's PCB socket repaired



    ecuXray1.jpg




    88na ECU as a control (both ECU's motherboard share same PN but the turbo ECU has has a daughter board on a flex cable)

    ecuXray2.jpg

    88NA ECU

    IC Socket - controlsm.jpg

    Repaired Turbo ECU: Darker lines are the wire that was stitched and soldered in place. Also found a trace (circled in red) on the top of the board that had been damaged that i didn't see.

    IC Socket - repairsm.jpg


    Zoomed out

    IC Socket - repair2sm.jpg


    Besides needing a separate power transistor replaced (dunno why it was blown), the ECU should be good to go.
    Last edited by Z_Karma; 12-10-2019, 05:11 PM.


    84 AE/Shiro #683/Shiro #820/84 Turbo
    • 1 like
  • #3
    wow thanks for posting that
  • #4
    pretty impressive. You sure are nice guy to help him out like that. Most people would of junked the ecu.
    Own:
    1986 Z31 2+0 Turbo GLL ---- spearco IC ,3" exhaust, Poly everything with solid subframe and diff mounts, HX35/40 Holset Turbo, CLSD, Nistune with 1220cc FIC injectors on E85.
    1993 Jeep Cherokee 4X4
    Owned:
    1995 Z32 2+0 NA Black
    1985 Z31 2+0 turbo Black
    1986 Z31 2+0 NA Red
    1988 Z31 2+2 NA Auto
    1988 Z31 2+0 Turbo White ---- Stripped for all of its goodies.
    1984 Z31 2+0 turbo Brown
    1985 Z31 2+0 NA Black
    2003 Nissan frontier D22 supercharded vg33e 4x4
  • #5
    Thanks, Yeah it probably should have been, but i enjoyed the challenge, especially if i learn something from it. It was also good excuse to get some training on our X-ray machine at work

    Well, we plugged the repaired ECU in with the nistune board installed and the fuel pump relay kept cycling on and off and the engine would not start. Not sure if there is other damage on the board besides the cracked transistor, which i replaced with one from another board.

    It's also possible there is other damage on the board or it could be that the nistune board doesn't have a tune on it. But to be certain i'm going to swap the nistune board over to the other ecu and see if it does the same thing. I've never used Nistune before and so i'm not sure what the issue is, but i do have another ecu in which to test it on.


    84 AE/Shiro #683/Shiro #820/84 Turbo
  • #6
    Wouldn't you want to X-ray the entire board? Could be really nice reference to have. I also had to replace one burnt component on one ECU. It left one damaged pad and we ran a wire to replace the connection. I did my best to find the other end correctly, but a board schematic would have helped a lot.

    Comment

    • Z_Karma
      #6.1
      Z_Karma commented
      12-18-2019, 12:32 PM
      Unfortunately our machine doesn't have the field of view to do the entire ECU. I could do it in sections maybe when/if i get better at using it but i had to solicit help from a coworker to do the scanning on this one.
  • #7
    Sort of resolved the issue by swapping the ECU motherboard. The part numbers for motherboards of the 88T and the 88-89NA ECU's are the same.

    I socketed the 88-89na board then removed the daughter board and Nistune type 1 from the 88T board and installed those onto the 88-89na motherboard.

    The car started up fine with whatever tune was on the Nistune.

    Evidently there is other damage to the 88T motherboard that i didn't find, so in the end, it was a learning experience.


    84 AE/Shiro #683/Shiro #820/84 Turbo