Forums/Z31P/z31-repairs-forums electronics/ECU repair for Nistune board install
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Z_Karma: (2019-12-10 20:34:51)
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
Z_Karma: (2019-12-10 20:37:08)
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.
dbruce: (2019-12-16 18:57:41)
wow thanks for posting that
Wilsonthesphere: (2019-12-18 00:53:12)
pretty impressive. You sure are nice guy to help him out like that. Most people would of junked the ecu.
Z_Karma: (2019-12-18 05:21:28)
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 [archived image: smile.png]
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.
kaur: (2019-12-18 07:10:23)
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.
Z_Karma: (2020-01-10 21:03:16)
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.