KZJ78 Tigris Writeup: ECU Rebuild/Upgrade with Pics (1 Viewer)

[FJ40 that green thing]

@Tigris that is awesome you tackled this. My ECU just failed on me last week, coincidentally right after I rebuilt the alternator. That probably isn't a coincidence? After unsuccessfully searching for a replacement that wasn't $1,000 or more and equally used condition, I found a shop willing to rebuild for approx. $200. I found your thread in the process, and I thought for a moment I may have to do this on my own if I can't find anyone with some electronics expertise to do it for me and I have to say I'm impressed. The damage looked pretty minor so I am hoping they can get it repaired easy enough. Will update in a couple weeks.

 

[Tigris]

@FJ40 that green thing
Thank you! And yes that is certainly not fun. I also suspect that the alternator job may have been the last straw for the ECU capacitors, but of course these old electrolytic caps are just going to fail and spew their guts sooner or later.

Having professionals do the job can be the right thing to do, but I must say that "professional" simply means that they will take money in exchange for service. Of course not all are equal.

What I have learned going through this process is that using the correct components is vital. For example not all electrolytic 33uf 60v 5000h 105° are the same, particularly when it come to ESR and series.

I still have the tags from the caps I used (known to be the right component with the best specs) and I can take a picture of these tags for you to source from Digikey. If I were you, even if you end up sending the ECU for a recap, I would send them the caps, this way they don't just use whatever unknown quality/specs replacement. Certified genuine components from Digikey are not at all expensive. $20 will buy them all.

Best of luck!

 

[specter]

@Tigris My KZJ78 is shifting the same way that you describe. Do you happen to have the P/N for the caps that you ordered from DigiKey? Would like to get them ordered so I have them on hand when I pull the ECU. Awesome write up by the way as well. Thank you in advance!

 

[Tigris]

@Tigris My KZJ78 is shifting the same way that you describe. Do you happen to have the P/N for the caps that you ordered from DigiKey? Would like to get them ordered so I have them on hand when I pull the ECU. Awesome write up by the way as well. Thank you in advance!

@specter

Thank you!

I am currently in the Caribbean. When I'm back on Monday I'll post the specs for the correct caps from Digikey.

Cheers!

 

[specter]

@Tigris Enjoy!!! Thank you so much!!!

 

[Tigris]

Okay, here is the list of correct caps as ordered from Digikey. Use the manufacturer # in the search and add them to the cart. Since these caps are very affordable I would suggest that you order two sets instead of one just in case you bugger one during install.

Good luck!

 

[specter]

@Tigris YOU ROCK!!!! Thank you so much!!!!! Also thank you for helping out the community!!!

 

[Tigris]

@specter
You are most welcome!! Glad to help..

Now, if you are attempting to do the recap yourself, remember to take your time cleaning. IPA and flux are your best friends.

Cheers!

 

[specter]

@Tigris it is going to be a bit before I recap the ECU since two of the caps are on backorder till Jan time frame. But they are on order!!!

 

[kzj78dp]

Okay, here is the list of correct caps as ordered from Digikey. Use the manufacturer # in the search and add them to the cart. Since these caps are very affordable I would suggest that you order two sets instead of one just in case you bugger one during install.

Good luck!

View attachment 3168939

View attachment 3168940

Okay, here is the list of correct caps as ordered from Digikey. Use the manufacturer # in the search and add them to the cart. Since these caps are very affordable I would suggest that you order two sets instead of one just in case you bugger one during install.

Good luck!

View attachment 3168939

View attachment 3168940

Tigris thanks for your great write up. I’m on Digikey to buy the caps, but I noticed that in the pictures of your original write up (first page), you have caps that are rated for 160V soldered on your board. Where as in your packaging list, they are 50V. Just wondering which ones I should order. Thanks again for taking the time to put all of this together!

 

[Tigris]

Tigris thanks for your great write up. I’m on Digikey to buy the caps, but I noticed that in the pictures of your original write up (first page), you have caps that are rated for 160V soldered on your board. Where as in your packaging list, they are 50V. Just wondering which ones I should order. Thanks again for taking the time to put all of this together!

Thanks @kzj78dp !

Yes you are correct. For my own ECU recap I opted for higher voltage/duty hours capacitors. That was an experiment that worked well since I knew that you can go up in the voltage but not the capacitance. Higher duty and temperature tolerances are never a bad thing to have.

Unfortunately I no longer have a reference for the caps I used on mine. But since then I recapped another ECU for a fellow Mudder as a favor and opted for the exact specs caps on his as I didn't know how my experiment would pan out long term. The values you see listed in the write up are those from this second recap I did, as I know that they are the correct ones for the job.

My ECU is working fine with the higher voltage caps. But some considerations must be made to accommodate for the physically larger sizes of the upgraded caps. So it's not for everyone.

Cheers!

 

[kzj78dp]

My ECU is working fine with the higher voltage caps. But some considerations must be made to accommodate for the physically larger sizes of the upgraded caps. So it's not for everyone.

Cheers!

Got it - thanks for the quick response!

 

[kzj78dp]

Is it recommended to change any of the non-electrolytic capacitors? Or, are those generally fine?

I came across a similar list for KZN130, which seems to be the same as the KZJ78, and they mention one 1uF / 50V Bipolar. Anyone know which one they are referring to?

 

[Tigris]

Is it recommended to change any of the non-electrolytic capacitors? Or, are those generally fine?

I came across a similar list for KZN130, which seems to be the same as the KZJ78, and they mention one 1uF / 50V Bipolar. Anyone know which one they are referring to?

View attachment 3209934

@kzj78dp

According to my research, all the non-electrolytic capacitors are okay to leave in circuit due to being manufactured using different formulation, lack of electrolyte, or the utilization of non degrading ingredients such as mica or tantalum.

Replacement of the 1uf bipolar capacitor was not suggested since it resembled an electrolytic capacitors only superficially. (It's also non polarized, i.e. can be installed in reverse).

That being said I did replace the bp capacitor when I recapped the two ECUs I worked on, mainly because the PCB was heavily corroded underneath it and I wasn't sure if the bp cap would survive the heat from the extraction and re-installation.

Heat management with new capacitors is a lot easier as you will have long leads to dissipate the heat.

Best of luck!

 

[FJ40 that green thing]

If anyone is interested, I found an ECU rebuilder for these KZJ's (part #89661-60250) in the USA at a reasonable cost if the thought of rebuilding yourself is outside of your comfort zone like it was for me. I feel like the amount of tools and supplies you would need and the time to do it would be a very last resort for me personally.

SIA Electronics, out of Illinois is who rebuilt mine. I talked to a guy named Zach who approved it so I shipped my ECU in right away. My board wasn't bad, just 1 or 2 leaking caps that caused a shorted trace that left me with no fuel/fuel pump issues leaving my vehicle inoperable. The cost was around $205 including shipping back to me which I thought was very reasonable. I was told they replace all the capacitors as a standard practice not just the leaking ones in addition to repairing the trace. The lead time was approximately 3-4 weeks. The ECU came back packaged well and warranty taped. Plugged it in and she started right up at the first turn of the key. I had a bit of trouble finding someone willing to rebuild a non-USA ECU but these guys were good to work with and apparently it was really no big deal. I am now searching for a spare to reduce any downtime in the future.

Here is a link to their website: ECM Repair | ECU Repair & Return Archives - SIA Electronics - https://siaelec.com/product-category/ecm-ecu-repair-return/

 

[srad751]

If anyone is interested, I found an ECU rebuilder for these KZJ's (part #89661-60250) in the USA at a reasonable cost if the thought of rebuilding yourself is outside of your comfort zone like it was for me. I feel like the amount of tools and supplies you would need and the time to do it would be a very last resort for me personally.

SIA Electronics, out of Illinois is who rebuilt mine. I talked to a guy named Zach who approved it so I shipped my ECU in right away. My board wasn't bad, just 1 or 2 leaking caps that caused a shorted trace that left me with no fuel/fuel pump issues leaving my vehicle inoperable. The cost was around $205 including shipping back to me which I thought was very reasonable. I was told they replace all the capacitors as a standard practice not just the leaking ones in addition to repairing the trace. The lead time was approximately 3-4 weeks. The ECU came back packaged well and warranty taped. Plugged it in and she started right up at the first turn of the key. I had a bit of trouble finding someone willing to rebuild a non-USA ECU but these guys were good to work with and apparently it was really no big deal. I am now searching for a spare to reduce any downtime in the future.

Here is a link to their website: ECM Repair | ECU Repair & Return Archives - SIA Electronics - https://siaelec.com/product-category/ecm-ecu-repair-return/

Not to Poo-Poo this thread, however, I am plagued w/ the dreaded ECU issue. My 96 KZJ78 randomly stalls, and sent the ECU to SIA electronics after I saw this thread and did some lite research. My experience went like this:

1 week after confirmed arrival: No call from them, I called, they said their systems were down, and were backed up and to allow 14 days for processing and repair.
Week 2 or day 14: Systems were still down and would not try and figure out where my ECU was or if they even had it.
Week 3 or day 21: Systems were finally up; however, no record of me ever sending an ECU to them. Had to email them the confirmation email I received from UPS w/ their employees signature.
Week 4 day 28: Systems were up, and they found my ECU, said it was logged into the system incorrectly, it was still with a technician.
Week 5 day 35: Systems were down, I requested that they go find my part and just send back to me.
Week 5 day 35: They called me back about an hour later and said my part was w/ technician and would be finished and sent to me by the upcoming Friday.
Week 5 day 35: They called me again and said my ECU was unrepairable; then asked me if I wanted the ECU back. I said yes, and they asked for another $25 to send back.
Week 5 day 37: Received ECU, still unrepaired, and I don't even think they opened it.

I would not use SIA again, however, if anyone has any suggestions on somewhere else i can send it to get repaired or buy a new one, I'm happy to try another place.

 

[oemhardtop]

Not to Poo-Poo this thread, however, I am plagued w/ the dreaded ECU issue. My 96 KZJ78 randomly stalls, and sent the ECU to SIA electronics after I saw this thread and did some lite research. My experience went like this:

1 week after confirmed arrival: No call from them, I called, they said their systems were down, and were backed up and to allow 14 days for processing and repair.
Week 2 or day 14: Systems were still down and would not try and figure out where my ECU was or if they even had it.
Week 3 or day 21: Systems were finally up; however, no record of me ever sending an ECU to them. Had to email them the confirmation email I received from UPS w/ their employees signature.
Week 4 day 28: Systems were up, and they found my ECU, said it was logged into the system incorrectly, it was still with a technician.
Week 5 day 35: Systems were down, I requested that they go find my part and just send back to me.
Week 5 day 35: They called me back about an hour later and said my part was w/ technician and would be finished and sent to me by the upcoming Friday.
Week 5 day 35: They called me again and said my ECU was unrepairable; then asked me if I wanted the ECU back. I said yes, and they asked for another $25 to send back.
Week 5 day 37: Received ECU, still unrepaired, and I don't even think they opened it.

I would not use SIA again, however, if anyone has any suggestions on somewhere else i can send it to get repaired or buy a new one, I'm happy to try another place.

I had an issue with my ECU (1994 KZJ78 with random stalls), so I sent it to Relentless Motorsports in TX where Joshua was able to fix it. While the repair was expensive and took three weeks to complete, this was during the holidays. I'm happy to report that the ECU is now working as it should, and I'm able to drive my vehicle again.

Plus, Joshua is highly experienced in fixing older JDM ECUs, and you can see on his Facebook page that he has successfully repaired many of them.

 

[FJ40 that green thing]

Not to Poo-Poo this thread, however, I am plagued w/ the dreaded ECU issue. My 96 KZJ78 randomly stalls, and sent the ECU to SIA electronics after I saw this thread and did some lite research. My experience went like this:

1 week after confirmed arrival: No call from them, I called, they said their systems were down, and were backed up and to allow 14 days for processing and repair.
Week 2 or day 14: Systems were still down and would not try and figure out where my ECU was or if they even had it.
Week 3 or day 21: Systems were finally up; however, no record of me ever sending an ECU to them. Had to email them the confirmation email I received from UPS w/ their employees signature.
Week 4 day 28: Systems were up, and they found my ECU, said it was logged into the system incorrectly, it was still with a technician.
Week 5 day 35: Systems were down, I requested that they go find my part and just send back to me.
Week 5 day 35: They called me back about an hour later and said my part was w/ technician and would be finished and sent to me by the upcoming Friday.
Week 5 day 35: They called me again and said my ECU was unrepairable; then asked me if I wanted the ECU back. I said yes, and they asked for another $25 to send back.
Week 5 day 37: Received ECU, still unrepaired, and I don't even think they opened it.

I would not use SIA again, however, if anyone has any suggestions on somewhere else i can send it to get repaired or buy a new one, I'm happy to try another place.

Hey, thats too bad. I am sorry you had that experience. The 1 experience I had with SIA worked out ok for me so I shared it on this thread due to the fact that out of contacting about 10 ECU rebuilders SIA was the only one willing to take a look at mine being non USA. Perhaps your ECU is unrepairable? attach pics here of your circuit board, maybe @Tigris or others can comment on that. Good luck in your search.

 

[Tigris]

As @FJ40 that green thing stated, it is unfortunate that you had this experience.

Also, X2 his idea...If you want, you can post a decent photo or two of the damaged area(s), this will help me assess if it's indeed unrepairable. Please keep in mind although I have the experience this is a tele-health appointment and I am not a doctor Only by having the ECU on hand that I can verify the status with full confidence using my multimeter. But I spent a long time starring at these things so it's worth the effort IMO

Best of luck!

 

[srad751]

As @FJ40 that green thing stated, it is unfortunate that you had this experience.

Also, X2 his idea...If you want, you can post a decent photo or two of the damaged area(s), this will help me assess if it's indeed unrepairable. Please keep in mind although I have the experience this is a tele-health appointment and I am not a doctor Only by having the ECU on hand that I can verify the status with full confidence using my multimeter. But I spent a long time starring at these things so it's worth the effort IMO

Best of luck!