Kahn's USDM 2JZGTE swap thread (aka The "Not Easy" Way)
#931
Instructor
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
funny i''m putting upgraded twins on my mk3 and a single for the sc ![Wink](https://www.clublexus.com/forums/images/smilies/wink.gif)
The twins I'm going with are JDM twins, and I had them serviced by Albert meads who put a billet compressor in
![Wink](https://www.clublexus.com/forums/images/smilies/wink.gif)
The twins I'm going with are JDM twins, and I had them serviced by Albert meads who put a billet compressor in
#933
Racer
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
Your thread has helped provide pictures and part numbers that I needed several times KahnBB6, thank you!
#935
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
I've held off on doing another thread update until some more progress was made (with pictures) but things are so slow going right now and my planning and investigation takes time so I figured I'd just put in a "short" (
) post here to cover what's been going on.
First off the SC is pretty much fine. Following some other work and ongoing house repairs I was finally looking forward to making some time to remove my old 160k mile used stock twin turbos and install the newly fully rebuilt ones that I have had set aside since around August 2020 after The Boost Lab in Tampa, FL had gone through both of my spare USDM CT12Bs that Gerry helped me find. I also took the time to restore a cast iron turbo Y collector and lower bypass valve housing as well. All of that has been ready to go in for months now.
I was also getting around to some minor paint and chip correction work. Looks like I'll be doing that pretty soon anyway with extra downtime.
...
The dreaded ignition failure and Cel Code 14 "Bad IGF Signal".... again (1 year since the last time):
Over two weeks ago I started up the car one evening and... you guessed it... I had a couple of very minor stumbles and finally the engine died once with a Code 14 "Bad IGF signal". I started the engine up again to let it idle and sure enough it happened again in under a minute. The igniter probably isn't 100% burned out yet but running it much more will make it burn out totally. I do have a brand new spare unused igniter unit but I have opted not to use it yet (for now).
Since I've been down this road before and with my finances diverted to other things right now I've just let sit for the time being until I address anything else in the electrical system to hopefully stop this nightmarish igniter burning issue.
This time it took a full year before it happened again. That's a new record but I also haven't been driving the car nearly as much in the last year due to minimizing travel while Covid-19 remains an issue. I do think less driving of the SC overall may be a factor but I'd have to compare my total mileage from last year to this year to have a clear idea of just how much of a factor it is.
....
Solutions I am trying now:
So here's what I'll be changing to address this now:
--I have moved any additional accessory connections from the fuse block direct battery positive terminal (under the cover) back to the battery positive terminal. For me this includes: Right and Left HID ballast positive power feeds, Mishimoto fan controller positive power feed to the OEM Supra TT auxiliary electric cooling fan and my relay positive feed for my custom fog light harness (had to add this since pre-1995's have no fog lights). My big 10-gauge 30A fused power feed wire going all the way back to the TT Fuel ECU area at the back seats feeding a 30/40A relay to power the Denso Supra TT fuel pump remains connected to the positive battery terminal as before.
--I have picked up a panel containing very compact four spot standard fuse locations + 1 standard relay location from a UK automotive parts supplier. That will arrive soon and I will be cleaning up all the above add-on electrical connections into a neat and clean little sub-fuse and relay block. The 10-gauge fuel pump positive feed wire will remain directly connected to the battery positive with its 30A-10ga fuse leading to the relay for that circuit.
--After a lot of research and advice I have ordered a DC Power 180-amp 6-phase alternator for JZ engines plus a set of custom made 2/0 charge and ground cables ("Big 3" cables) which I will add in addition to the existing major alternator charge and ground connections.
...
Alternator and "Big 3" cables:
I have long suspected that the original used OEM Supra TT 6-speed 90-amp 3-phase alternator either didn't put out enough juice or possibly over-charged at one point causing potential damage to something in the ignition system.
Replacing that with a "new" Toyota dealer remanufactured Supra TT Automatic 100-amp 3-phase alternator over a year ago seems to have helped a bit but really didn't put out enough juice to power the car's amperage demands... at idle anyway.
When using my turn signals or hazards the engine idle would fluctuate rhythmically and the voltmeter's needle would go from 13.2-13.0V to 12.5V and back again like a ticking clock. One some occasions it was worse which did worry me but it never consistently stayed worse.
As Lexus2000 has been doing amazing investigative work and experimentation on a 1992-1994 SC300/400 flasher relay alternative it has become even more apparent just how much power draw even the stock SC turn signals and hazards take up: https://www.clublexus.com/forums/per...0-24020-a.html
...And this has further fueled my thinking that, for whatever reason, I have needed to upgrade to a 130-amp 6-phase Tundra/Sequoia/GX470/later-SC340 or other factory 6-phase alternator or a good aftermarket 6-phase one like a Mechman or DC Power.
So doing that to provide extremely stable amperage and voltage and big gauge additional electrical cables is one part of my solution.
No matter what I feel this is something I need to do. When I look at my voltmeter gauge the needle should not move at all once the alternator and its voltage regulator have heated up to operating temperature. They all start around 14V or so and settle to 13.5-13.8V but a healthy charging and electrical system should have a consistent and unwavering number of volts under load.
I like this brief but SC300/400 specific DIY guide explaining how any why the factory grounds and charging wires should be upgraded (rather added to) given the age of our SC's and Soarers:
.....
I didn't realize the importance of this when I first completed my swap three years ago but since then I have come to know better. Switching to a better and more modern alternator design should have been an early priority with this swap project.
I never had this igniter burning issue with my original unmodified engine but I also had no electric auxiliary fan. I did have a very mild version of the power draw of the flashers and hazards slightly affecting the idle of the 2JZ-GE distributor ignition engine however but it was not as pronounced as it became once I started up my 2JZ-GTE swap engine.
....
New igniter & possibly replacing the igniter "A" and "B" connectors:
This one is obvious. The recurring issue has nearly burned out yet another TT non-VVT-i igniter so I have to install a new one. I'll buy another one as a new spare and install the brand new unused one that I already have.
Also, since I had that extremely weird issue a while back when I first started my engine where I had to replace an injector connector because while both electrical wires for it checked out the old plastic connector housing itself had become slightly electrically conductive(?!) I may do the same with my igniter "A" and "B" connectors. I already have both of these and it's not a big deal to transfer over each wire to the new housing and inspect all those wires yet again while I'm at it. But it sure is a long shot because of course plastic does not conduct electricity.
...
New coil packs (more on this reasoning later):
This will be an ignition system component that has NOT been changed before. The Denso brand (not OEM Toyota but the same thing) TT non-vvt-i ignition coils I have installed were bought brand new for this engine at the time I first started it up. I have read in the past that Denso brand TT ignition coils are considered "B-Grade" whereas Toyota OEM ignition coils are considered "A-Grade" but nearly everyone I have spoken to has told me that Denso TT coil packs are not known to present issues for them.
Nonetheless, whether I get six new Denso coil packs from Rockauto or buy them as OEM from a Toyota dealer I will now replace the ones I have despite only having barely 6k miles on them.
Reasoning: I really still do not know how such a thing could have occurred but *IF* one or more of my coil packs could have been damaged in some way causing an open short on an internal secondary winding... apparently THAT could indeed cause harm to an igniter control unit... or possibly even the main ECU's ignition driver circuit Mosfets (basically 6 internal switching relays that the ECU's little ignition microchip IC uses to execute pre-determined firing order based on other sensor inputs to the ECU such as the crank angle sensor and cam sensors).
I am not the only person who has had this issue but it is a VERY rare problem to have and there is almost no documentation on it in the JZ vehicle community. Here's a thread I've been communicating in on Supraforums regarding the extremely few others who had experienced this TT igniter burning issue:
https://www.supraforums.com/threads/...#post-13931549
And within that thread, here are the two videos I found during my research to learn about ignition systems that lead me to this concern. They are NOT Toyota or 2JZ-GTE specific but the basic electronic ignition principles still apply. Both videos are good to watch all the way through:
Just in case any new readers don't recall from this build's history many threads back, there was a misfiring issue I had upon initial startup with a couple of cylinders (I have forgotten which couple at this point but pages back it is thoroughly documented) and I did address these issues which were due to faulty wiring in the engine harness that I never discovered until I'd installed it onto my new engine.
I can't say for sure but it's possible that something resulting from this could have also caused some issue with one or more of my coil packs leading to some internal short that isn't noticeable at idle or even at high engine speeds.
Or... it's very unlikely but technically possible that I have a defective ignition coil that otherwise seems fine at idle and low engine load. I say unlikely because you just don't hear about defective 1JZ/2JZ TT ignition coil packs. Worn out coil packs after a LOT of mileage but not so much defective TT coil packs.
Either way my suspicion is that something is technically wrong with one or more of the ones I have installed even though it does not seem like it in normal use.
I'll also note that since my 2nd turbo (used 150k mile set) has been non-functional since the first time I started my engine I have seldom gone over 3800-4000RPM. Only a couple of times a long while back did I go to 5k rpm with the 2nd turbo whining. So any ignition breakup at those elevated RPMs will always have been obscured by the turbo failure issue.
And before this igniter burn issue showed up again I was just getting ready to finally replace both turbochargers with new ones, so...
....
I will possibly look into yet another ECU but after I investigate whether it is possible to replace the six Mosfets inside the current one:
This is probably going to be a final effort after all of the above. I don't *think* it's possible for an ECU with affected ignition driver Mosfets to cause any damage to the rest of the ignition system once everything else in the charging and ignition system have been effectively replaced. The Mosfets themselves *should* be possible to source brand new and I've watched several videos showing how to replace them on numerous vehicle ECUs. The main question would be whether or not the little ignition chip that controls the Mosfets could have sustained any damage. Likely that is a proprietary Denso chip and I could only hope that a donor from a cheap Aristo 2JZ-GTE ECU would be the same.
But... I'm not that far along yet. Getting into ECU ignition driver Mosfet replacements may be the final thing I do but I now know for a fact that after using a couple of these ECUs the actual root cause of the igniter burning issue is something else.
...
Current hypothesis (see what I did there?):
Whatever started this issue in the first place I am 99% certain that my engine wiring harness is okay. I have previously gone through the entire ignition circuit wiring, injector wiring and other connections between engine sensors, components and the main ECU several times and have repaired any issues that I found.
I think this may have been caused early on by the engine misfiring which did not get fully fixed right away.
The old used 90-amp 3-phase OEM alternator *MAY* have overcharged and caused one or more issues initially but the only remaining potential culprit component would have to be the ignition coil packs. If some open short has been present in one or more of them all along then this issue was going to keep persisting and it probably would be likely to happen faster the harder and more frequently I drive my car and slower the less frequently and more relaxed that I drive my car.
If neither the old used 90-amp alternator or 100-amp alternator were up to handling the full electrical power draw my SC300 has demanded all along then it might be possible, especially with the voltmeter needle rhythmically bounding over and over again at every use of the turn signals and hazards, for some mild long term voltage spiking or irregularity to affect each igniter unit that I have used to date.
I still have no good answer to what is actually going on but I do know that a more stable electrical charging and ground system can only help my car and after speaking to Aaron at Driftmotion and reading many other online forum threads pointing to a bad/compromised ignition coil or all bad coils potentially damaging an igniter and potentially even an ECU's ignition driver circuit (hopefully just the Mosfets), I am going to buy all new igniters and spark plugs and install those as well.
....
I'm so ready for this issue to be over with and solved for good. I really hope this multi-pronged approach does it. In the meantime I'm holding off with driving my SC until I can make all the necessary changes.
If at long last the approach of throwing the kitchen sink at it doesn't work and this happens yet again I will spend the money on a complete USDM TT OBD1 6-speed to SC300 engine harness build from Tweak'd Performance and install that.
There really is nothing else left to replace once you go that far![Smilie](https://www.clublexus.com/forums/images/smilies/smile.gif)
...
The DC Power 180-amp alternator, new charge and ground cables and the super compact extra fuse and relay sub-box all show up next week and I'll get to installing those.
I'll post pictures of that install. Sorry there are no pictures for the last few posts.
After a little break I'll order the new TT ignition coil packs, a new set of Denso 5304 IK20 plugs and a new TT non-vvt-i igniter and install those.
Then I'll see how it goes from there.
In the meantime I'm going to get to some of the minor paint correction as planned and also start looking at the internal ignition Mosfets on my first 6-speed ECU which was capacitor serviced several years back and which I haven't been using for a couple of years now. At the very least I'll learn something from inspecting it.
![Embarrassment](https://www.clublexus.com/forums/images/smilies/redface.gif)
First off the SC is pretty much fine. Following some other work and ongoing house repairs I was finally looking forward to making some time to remove my old 160k mile used stock twin turbos and install the newly fully rebuilt ones that I have had set aside since around August 2020 after The Boost Lab in Tampa, FL had gone through both of my spare USDM CT12Bs that Gerry helped me find. I also took the time to restore a cast iron turbo Y collector and lower bypass valve housing as well. All of that has been ready to go in for months now.
I was also getting around to some minor paint and chip correction work. Looks like I'll be doing that pretty soon anyway with extra downtime.
...
The dreaded ignition failure and Cel Code 14 "Bad IGF Signal".... again (1 year since the last time):
Over two weeks ago I started up the car one evening and... you guessed it... I had a couple of very minor stumbles and finally the engine died once with a Code 14 "Bad IGF signal". I started the engine up again to let it idle and sure enough it happened again in under a minute. The igniter probably isn't 100% burned out yet but running it much more will make it burn out totally. I do have a brand new spare unused igniter unit but I have opted not to use it yet (for now).
Since I've been down this road before and with my finances diverted to other things right now I've just let sit for the time being until I address anything else in the electrical system to hopefully stop this nightmarish igniter burning issue.
This time it took a full year before it happened again. That's a new record but I also haven't been driving the car nearly as much in the last year due to minimizing travel while Covid-19 remains an issue. I do think less driving of the SC overall may be a factor but I'd have to compare my total mileage from last year to this year to have a clear idea of just how much of a factor it is.
....
Solutions I am trying now:
So here's what I'll be changing to address this now:
--I have moved any additional accessory connections from the fuse block direct battery positive terminal (under the cover) back to the battery positive terminal. For me this includes: Right and Left HID ballast positive power feeds, Mishimoto fan controller positive power feed to the OEM Supra TT auxiliary electric cooling fan and my relay positive feed for my custom fog light harness (had to add this since pre-1995's have no fog lights). My big 10-gauge 30A fused power feed wire going all the way back to the TT Fuel ECU area at the back seats feeding a 30/40A relay to power the Denso Supra TT fuel pump remains connected to the positive battery terminal as before.
--I have picked up a panel containing very compact four spot standard fuse locations + 1 standard relay location from a UK automotive parts supplier. That will arrive soon and I will be cleaning up all the above add-on electrical connections into a neat and clean little sub-fuse and relay block. The 10-gauge fuel pump positive feed wire will remain directly connected to the battery positive with its 30A-10ga fuse leading to the relay for that circuit.
--After a lot of research and advice I have ordered a DC Power 180-amp 6-phase alternator for JZ engines plus a set of custom made 2/0 charge and ground cables ("Big 3" cables) which I will add in addition to the existing major alternator charge and ground connections.
...
Alternator and "Big 3" cables:
I have long suspected that the original used OEM Supra TT 6-speed 90-amp 3-phase alternator either didn't put out enough juice or possibly over-charged at one point causing potential damage to something in the ignition system.
Replacing that with a "new" Toyota dealer remanufactured Supra TT Automatic 100-amp 3-phase alternator over a year ago seems to have helped a bit but really didn't put out enough juice to power the car's amperage demands... at idle anyway.
When using my turn signals or hazards the engine idle would fluctuate rhythmically and the voltmeter's needle would go from 13.2-13.0V to 12.5V and back again like a ticking clock. One some occasions it was worse which did worry me but it never consistently stayed worse.
As Lexus2000 has been doing amazing investigative work and experimentation on a 1992-1994 SC300/400 flasher relay alternative it has become even more apparent just how much power draw even the stock SC turn signals and hazards take up: https://www.clublexus.com/forums/per...0-24020-a.html
...And this has further fueled my thinking that, for whatever reason, I have needed to upgrade to a 130-amp 6-phase Tundra/Sequoia/GX470/later-SC340 or other factory 6-phase alternator or a good aftermarket 6-phase one like a Mechman or DC Power.
So doing that to provide extremely stable amperage and voltage and big gauge additional electrical cables is one part of my solution.
No matter what I feel this is something I need to do. When I look at my voltmeter gauge the needle should not move at all once the alternator and its voltage regulator have heated up to operating temperature. They all start around 14V or so and settle to 13.5-13.8V but a healthy charging and electrical system should have a consistent and unwavering number of volts under load.
I like this brief but SC300/400 specific DIY guide explaining how any why the factory grounds and charging wires should be upgraded (rather added to) given the age of our SC's and Soarers:
.....
I didn't realize the importance of this when I first completed my swap three years ago but since then I have come to know better. Switching to a better and more modern alternator design should have been an early priority with this swap project.
I never had this igniter burning issue with my original unmodified engine but I also had no electric auxiliary fan. I did have a very mild version of the power draw of the flashers and hazards slightly affecting the idle of the 2JZ-GE distributor ignition engine however but it was not as pronounced as it became once I started up my 2JZ-GTE swap engine.
....
New igniter & possibly replacing the igniter "A" and "B" connectors:
This one is obvious. The recurring issue has nearly burned out yet another TT non-VVT-i igniter so I have to install a new one. I'll buy another one as a new spare and install the brand new unused one that I already have.
Also, since I had that extremely weird issue a while back when I first started my engine where I had to replace an injector connector because while both electrical wires for it checked out the old plastic connector housing itself had become slightly electrically conductive(?!) I may do the same with my igniter "A" and "B" connectors. I already have both of these and it's not a big deal to transfer over each wire to the new housing and inspect all those wires yet again while I'm at it. But it sure is a long shot because of course plastic does not conduct electricity.
...
New coil packs (more on this reasoning later):
This will be an ignition system component that has NOT been changed before. The Denso brand (not OEM Toyota but the same thing) TT non-vvt-i ignition coils I have installed were bought brand new for this engine at the time I first started it up. I have read in the past that Denso brand TT ignition coils are considered "B-Grade" whereas Toyota OEM ignition coils are considered "A-Grade" but nearly everyone I have spoken to has told me that Denso TT coil packs are not known to present issues for them.
Nonetheless, whether I get six new Denso coil packs from Rockauto or buy them as OEM from a Toyota dealer I will now replace the ones I have despite only having barely 6k miles on them.
Reasoning: I really still do not know how such a thing could have occurred but *IF* one or more of my coil packs could have been damaged in some way causing an open short on an internal secondary winding... apparently THAT could indeed cause harm to an igniter control unit... or possibly even the main ECU's ignition driver circuit Mosfets (basically 6 internal switching relays that the ECU's little ignition microchip IC uses to execute pre-determined firing order based on other sensor inputs to the ECU such as the crank angle sensor and cam sensors).
I am not the only person who has had this issue but it is a VERY rare problem to have and there is almost no documentation on it in the JZ vehicle community. Here's a thread I've been communicating in on Supraforums regarding the extremely few others who had experienced this TT igniter burning issue:
https://www.supraforums.com/threads/...#post-13931549
And within that thread, here are the two videos I found during my research to learn about ignition systems that lead me to this concern. They are NOT Toyota or 2JZ-GTE specific but the basic electronic ignition principles still apply. Both videos are good to watch all the way through:
Just in case any new readers don't recall from this build's history many threads back, there was a misfiring issue I had upon initial startup with a couple of cylinders (I have forgotten which couple at this point but pages back it is thoroughly documented) and I did address these issues which were due to faulty wiring in the engine harness that I never discovered until I'd installed it onto my new engine.
I can't say for sure but it's possible that something resulting from this could have also caused some issue with one or more of my coil packs leading to some internal short that isn't noticeable at idle or even at high engine speeds.
Or... it's very unlikely but technically possible that I have a defective ignition coil that otherwise seems fine at idle and low engine load. I say unlikely because you just don't hear about defective 1JZ/2JZ TT ignition coil packs. Worn out coil packs after a LOT of mileage but not so much defective TT coil packs.
Either way my suspicion is that something is technically wrong with one or more of the ones I have installed even though it does not seem like it in normal use.
I'll also note that since my 2nd turbo (used 150k mile set) has been non-functional since the first time I started my engine I have seldom gone over 3800-4000RPM. Only a couple of times a long while back did I go to 5k rpm with the 2nd turbo whining. So any ignition breakup at those elevated RPMs will always have been obscured by the turbo failure issue.
And before this igniter burn issue showed up again I was just getting ready to finally replace both turbochargers with new ones, so...
....
I will possibly look into yet another ECU but after I investigate whether it is possible to replace the six Mosfets inside the current one:
This is probably going to be a final effort after all of the above. I don't *think* it's possible for an ECU with affected ignition driver Mosfets to cause any damage to the rest of the ignition system once everything else in the charging and ignition system have been effectively replaced. The Mosfets themselves *should* be possible to source brand new and I've watched several videos showing how to replace them on numerous vehicle ECUs. The main question would be whether or not the little ignition chip that controls the Mosfets could have sustained any damage. Likely that is a proprietary Denso chip and I could only hope that a donor from a cheap Aristo 2JZ-GTE ECU would be the same.
But... I'm not that far along yet. Getting into ECU ignition driver Mosfet replacements may be the final thing I do but I now know for a fact that after using a couple of these ECUs the actual root cause of the igniter burning issue is something else.
...
Current hypothesis (see what I did there?):
Whatever started this issue in the first place I am 99% certain that my engine wiring harness is okay. I have previously gone through the entire ignition circuit wiring, injector wiring and other connections between engine sensors, components and the main ECU several times and have repaired any issues that I found.
I think this may have been caused early on by the engine misfiring which did not get fully fixed right away.
The old used 90-amp 3-phase OEM alternator *MAY* have overcharged and caused one or more issues initially but the only remaining potential culprit component would have to be the ignition coil packs. If some open short has been present in one or more of them all along then this issue was going to keep persisting and it probably would be likely to happen faster the harder and more frequently I drive my car and slower the less frequently and more relaxed that I drive my car.
If neither the old used 90-amp alternator or 100-amp alternator were up to handling the full electrical power draw my SC300 has demanded all along then it might be possible, especially with the voltmeter needle rhythmically bounding over and over again at every use of the turn signals and hazards, for some mild long term voltage spiking or irregularity to affect each igniter unit that I have used to date.
I still have no good answer to what is actually going on but I do know that a more stable electrical charging and ground system can only help my car and after speaking to Aaron at Driftmotion and reading many other online forum threads pointing to a bad/compromised ignition coil or all bad coils potentially damaging an igniter and potentially even an ECU's ignition driver circuit (hopefully just the Mosfets), I am going to buy all new igniters and spark plugs and install those as well.
....
I'm so ready for this issue to be over with and solved for good. I really hope this multi-pronged approach does it. In the meantime I'm holding off with driving my SC until I can make all the necessary changes.
If at long last the approach of throwing the kitchen sink at it doesn't work and this happens yet again I will spend the money on a complete USDM TT OBD1 6-speed to SC300 engine harness build from Tweak'd Performance and install that.
There really is nothing else left to replace once you go that far
![Smilie](https://www.clublexus.com/forums/images/smilies/smile.gif)
...
The DC Power 180-amp alternator, new charge and ground cables and the super compact extra fuse and relay sub-box all show up next week and I'll get to installing those.
I'll post pictures of that install. Sorry there are no pictures for the last few posts.
After a little break I'll order the new TT ignition coil packs, a new set of Denso 5304 IK20 plugs and a new TT non-vvt-i igniter and install those.
Then I'll see how it goes from there.
In the meantime I'm going to get to some of the minor paint correction as planned and also start looking at the internal ignition Mosfets on my first 6-speed ECU which was capacitor serviced several years back and which I haven't been using for a couple of years now. At the very least I'll learn something from inspecting it.
![Uhh...](https://www.clublexus.com/forums/images/smilies/1387914497.gif)
Last edited by KahnBB6; 11-22-20 at 07:59 PM.
#936
Lexus Fanatic
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
This is probably going to be a final effort after all of the above. I don't *think* it's possible for an ECU with affected ignition driver Mosfets to cause any damage to the rest of the ignition system once everything else in the charging and ignition system have been effectively replaced. The Mosfets themselves *should* be possible to source brand new and I've watched several videos showing how to replace them on numerous vehicle ECUs. The main question would be whether or not the little ignition chip that controls the Mosfets could have sustained any damage. Likely that is a proprietary Denso chip and I could only hope that a donor from a cheap Aristo 2JZ-GTE ECU would be the same.
On replacing the MOSFETs they are likely easy to source, but again with a MOSFET generally it either works or it doesn't they don't tolerate shorts well at all due to the very low internal resistance. A standard transistor can take a short and get baking hot but still work a MOSFET will burn out basically instantly. What I don't know is how or if a MOSFET degrades after switching billions of times. In theory everything wears out, "solid state" or not.
#937
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
I've blown up many MOSFETs testing and building various circuits, they almost always end up a dead short between drain and source but once in a while the entire thing ended up shorting, all pins to each other. Or sometimes they blow their tops off. If there is a short involving the gate then it is possible the chip driving the gate could be damaged. The thing is, damage means the chip is killed not half working that's hard to do with any silicon component. I've fried LEDs where they were super dim but then they burnt out shortly after. Some CMOS gates can be partially toasted, they still work but can hardly drive any current so I guess it is possible to partially damage the chip that drives the MOSFETs. But my gut says the ECU has all kinds of protection built in to prevent such things.
On replacing the MOSFETs they are likely easy to source, but again with a MOSFET generally it either works or it doesn't they don't tolerate shorts well at all due to the very low internal resistance. A standard transistor can take a short and get baking hot but still work a MOSFET will burn out basically instantly. What I don't know is how or if a MOSFET degrades after switching billions of times. In theory everything wears out, "solid state" or not.
On replacing the MOSFETs they are likely easy to source, but again with a MOSFET generally it either works or it doesn't they don't tolerate shorts well at all due to the very low internal resistance. A standard transistor can take a short and get baking hot but still work a MOSFET will burn out basically instantly. What I don't know is how or if a MOSFET degrades after switching billions of times. In theory everything wears out, "solid state" or not.
It's good to know that these parts are likely easily sourced and replaced (I see an electronics heat gun being used in online guides rather than an ESD-safe soldering iron). Given how overkill Toyota tends to be with their electronics designs I am also with you in thinking that there are probably protections in place to keep the microchip components safe from electrical overloads.
I have three identical ECUs and each of them has been used during a time when this igniter burnout, ignition shutdown and ignition no-start condition has happened. I have not yet inspected my very first ECU which went through this (and which I had professionally capacitor serviced at Driftmotion prior to using it) but my second identical ECU which also was in use during a subsequent igniter burnout last year was sent in to Tanin Auto Electronix for capacitor servicing and inspection. They reported no visual abnormalities with the circuit boards and there was no electrolytic fluid leak from the original capacitors either. I think if they had seen any visual damage to any of the six MOSFETs on the ignition driver circuitry they would have alerted me to it and offered to replace those while that ECU was in for service.
Compared to modern ignition coils with three wires (Power, ECU Switching Ground and the third for "control") these older two-wire ignition coils use the external 1JZGTE/2JZGTE igniter unit near the engine bay shock tower to communicate with the ECU's for IGF signal firing confirmation and it is that under-hood igniter unit that doles out all +12V electrical pulses to the positive wire terminal of each coil pack. Then the negative terminal of each coil pack wire goes through the engine harness and directly to each of the six ECU ignition ground switches (which must be internal ECU MOSFETs). I don't think it makes much difference in this case but this ECU's system uses sequential ignition rather than the batch-fire ignition of the early 1JZ-GTE's.
I will inspect my first ECU and my hope is to see no visible damage to the ignition driver MOSFETs at all.
After going through this issue a number of times already despite many efforts to address fixing the real issue my hunches for possibilities are:
--insufficient low RPM power from the factory 3-phase alternator causing voltage fluctuations over time may have affected something over time
--Or my first alternator rated at only 90-Amps and 3-phase may have over-charged at some point without my knowing it and affected something... possibly one or more of the six ignition coil packs (a slight open short on the secondary internal wiring of one of them perhaps).
--early first engine start and break in where there was some misfiring that had to be corrected wire-by-wire may have affected something such as one or more of the coil packs (again this would have to be a slight but otherwise seemingly functional open short on the secondary internal wiring of one or more coil packs).
--extremely unlikely and rare if at all the case but I may have a defective coil pack which seems fine in normal use. This is very unlikely knowing the quality of Denso components but at this point I can't rule it out until I replace the entire set.
--An already weak factory ground wire somewhere in the engine bay, despite looking fine and being hooked up correctly could be causing a weak ground condition either constantly or under some circumstances where whatever grounding it does provide becomes insufficient (high RPM or perhaps during any period of very high current draw such as when my auxiliary cooling fan is on, when the HID headlight ballasts are on or when my factory turn signal bulbs or hazard flasher mode are used).
The issue, whatever it is, will be right under my nose but has not been easy to definitively nail down.
If there is anything to worry about with one of my ECU's (hopefully not though) then I hope Toyota engineers did work in enough extra protection to prevent any of the little chips from getting any over-current condition under extreme circumstances.
Now that particular question is one I would pose to CL member Yamae since he worked on Toyota engine ECU design during the time these 1JZ-GTE and 2JZ-GTE ECUs were first designed and produced. He's not around here often and is retired now but it may be worth asking him his thoughts if nothing else I try fully solves my issue.
But hopefully the issue (and damage) is going to be far simpler to fix than ECU surgery.
...
By the way your 92-94 SC flasher relay alternative prototype is fast on its way and should arrive by the start of the week. I'll contact you back about it over PM tomorrow.
Last edited by KahnBB6; 11-22-20 at 08:48 PM.
#938
Lexus Fanatic
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I've seen the igniter go out on Camry's and ES300's, this one
https://www.ebay.com/itm/202826353982
Having an external module to do the heavy lifting is a great idea. BTW the safest way to remove those MOSFETs (at least for me) is cutting the legs and pulling them out via soldering iron versus hot air or solder sucking. BTW the great thing about a MOSFET is the gate can be driven with very little current meaning you can have very high resistance between the gate and whatever is driving it, makes it easy to protect the low current components. I'm curious who makes the MOSFETs in that ECU, if I had to guess I'd say NEC.
Do you have a part number of the original coils? Is it 90919-02205?
https://www.ebay.com/itm/202826353982
Having an external module to do the heavy lifting is a great idea. BTW the safest way to remove those MOSFETs (at least for me) is cutting the legs and pulling them out via soldering iron versus hot air or solder sucking. BTW the great thing about a MOSFET is the gate can be driven with very little current meaning you can have very high resistance between the gate and whatever is driving it, makes it easy to protect the low current components. I'm curious who makes the MOSFETs in that ECU, if I had to guess I'd say NEC.
Do you have a part number of the original coils? Is it 90919-02205?
#939
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
I've seen the igniter go out on Camry's and ES300's, this one
https://www.ebay.com/itm/202826353982
Having an external module to do the heavy lifting is a great idea. BTW the safest way to remove those MOSFETs (at least for me) is cutting the legs and pulling them out via soldering iron versus hot air or solder sucking. BTW the great thing about a MOSFET is the gate can be driven with very little current meaning you can have very high resistance between the gate and whatever is driving it, makes it easy to protect the low current components. I'm curious who makes the MOSFETs in that ECU, if I had to guess I'd say NEC.
Do you have a part number of the original coils? Is it 90919-02205?
https://www.ebay.com/itm/202826353982
Having an external module to do the heavy lifting is a great idea. BTW the safest way to remove those MOSFETs (at least for me) is cutting the legs and pulling them out via soldering iron versus hot air or solder sucking. BTW the great thing about a MOSFET is the gate can be driven with very little current meaning you can have very high resistance between the gate and whatever is driving it, makes it easy to protect the low current components. I'm curious who makes the MOSFETs in that ECU, if I had to guess I'd say NEC.
Do you have a part number of the original coils? Is it 90919-02205?
The part about all of this that nags me is the very clear predictably inconsistent voltage (and presumably amperage) the car has been getting all along which became measurable all the time while driving once I installed a voltmeter in the dashboard.
Maybe alternators not up to the task have contributed. Maybe my first (used) alternator overcharged (still not sure if it did or not). And maybe the factory 29 year old ground connections need upgrading with the additional 2/0 cables I've ordered.
I've never seen that Camry/ES igniter before. Interesting that it has a connector on both sides. The one for 1992-1997 2JZ-GE engines is very small. My 1993 original 2JZ-GE igniter was totally good when I sold it.
This is the style for 1JZ-GTE and 2JZ-GTE Non-VVT-i's... Toyota P/N 89621-22030 (Not mine, just an example picture):
![](https://cimg3.ibsrv.net/gimg/www.clublexus.com-vbulletin/1600x1200/s_l1600_fc5e183497b2955d69dcbcc8f7c83e22c537a436.jpg)
Yes, the OEM Toyota coil packs are P/N 90919-02205. The Denso aftermarket version of those (I only go through Rockauto or DensoProducts) is 673-1200. Since Denso makes them for Toyota they look identical other than that they have no Toyota logo or Toyota part number molded into their plastic casings. They also cost a lot less than the ones with a Toyota part number (about $58 Denso vs OEM $96-$127 depending on the dealer).
......
Interesting that you do not use a solder sucking gun, pump or hot air gun. I can't justify investing in an expensive Hakko desoldering gun so I have used a cheap Velleman desoldering pump and then removed excess solder with a wick strip and my iron (a Hakko FX-888D station). For a hot air I was looking at getting a Newacalox 858D since it's very affordable but maybe it needs a far more concentrated tip for fine electronics.
Previously I would do what you have done and use my main soldering iron, a wick and whatever is good enough to grab a component from the board with. You do this work professionally and you feel the regular soldering iron method is the safest way so I'm giving pause now on ordering a concentrated heat gun
![Wink](https://www.clublexus.com/forums/images/smilies/wink.gif)
When I get into that spare main ECU I'll show you what I find. You'll probably be right about NEC making the MOSFETs. If there's a part number listed on them I should be able to order new ones should they be needed
![Smilie](https://www.clublexus.com/forums/images/smilies/smile.gif)
And you're right about even solid state electronic components being subject to wear and tear. We always hope little microchips last forever as electronics get into vintage age ranges.
Last edited by KahnBB6; 11-22-20 at 10:23 PM.
#940
Lexus Fanatic
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Especially the ones used by 2JZ-GE's, 2JZ-GTE's and 1JZ's... both non-VVT-i and VVT-i variants and regardless of there being a distributor ignition or coil on plug ignition. But especially a brand new igniter shouldn't go out within 3-4 weeks... as used to be the case with my car. This time it just took one whole year from the very last time it happened to me.
This is the style for 1JZ-GTE and 2JZ-GTE Non-VVT-i's... Toyota P/N 89621-22030 (Not mine, just an example picture):
[-- [image --]
[-- [image --]
Yes, the OEM Toyota coil packs are P/N 90919-02205. The Denso aftermarket version of those (I only go through Rockauto or DensoProducts) is 673-1200. Since Denso makes them for Toyota they look identical other than that they have no Toyota logo or Toyota part number molded into their plastic casings. They also cost a lot less than the ones with a Toyota part number (about $58 Denso vs OEM $96-$127 depending on the dealer).
Interesting that you do not use a solder sucking gun, pump or hot air gun. I can't justify investing in an expensive Hakko desoldering gun so I have used a cheap Velleman desoldering pump and then removed excess solder with a wick strip and my iron (a Hakko FX-888D station). For a hot air I was looking at getting a Newacalox 858D since it's very affordable but maybe it needs a far more concentrated tip for fine electronics.
When I get into that spare main ECU I'll show you what I find. You'll probably be right about NEC making the MOSFETs. If there's a part number listed on them I should be able to order new ones should they be needed
![Smilie](https://www.clublexus.com/forums/images/smilies/smile.gif)
#941
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Spikey power from the taxed 3-phase alternator, a potential issue with one of the main factory ground connections or a Denso coil pack with a defect or damage causing a slight "scar" where an open short crossover can occur inside them are my three suspicions at this point. Maybe it's a combination of two of those or all three but it's likely to be one of those.
The igniter connectors on my SC's 2JZ-GTE engine harness look much better and so do the wires going into them and the rubber boot grommets. Still, I am probably going to replace both connectors with new ones at this point. It cannot hurt to do so and they didn't cost much to pick up.
Those are good tools. My approach when working on a rare (or maybe delicate) board is use the method that is least likely to cause damage which in my case is doing it old school. That said the PCBs Toyota uses are incredibly well made, maybe the best I've ever worked on. For SMD work you need a hot air device, well you don't HAVE to but it is way easier.
Oh, I'm definitely not removing or replacing any electronic component inside a Toyota ECU unless I can find a source for the same exact part brand new. I would never chance it with anything less.
#942
Lexus Fanatic
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I know, but seeing that made me wonder if you are having a similar thing happen. But...sounds like you're good.
What about the terminals? You can restore them by soaking in Evapo-Rust they come out like new. The stuff is supposed to be only for removing iron (rust) but it works on connector terminals as well. Maybe there is something else that is more appropriate?
What you are thinking of, surface mounted device.
Have you tried to go through all the ground points and check them? Is there a ground point on the intake manifold anywhere?
The igniter connectors on my SC's 2JZ-GTE engine harness look much better and so do the wires going into them and the rubber boot grommets.
Still, I am probably going to replace both connectors with new ones at this point. It cannot hurt to do so and they didn't cost much to pick up.
What does "SMD" mean as you're using the term? I'm 99% sure I know what you're referring to though.
Have you tried to go through all the ground points and check them? Is there a ground point on the intake manifold anywhere?
#943
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
I know, but seeing that made me wonder if you are having a similar thing happen. But...sounds like you're good.
What about the terminals? You can restore them by soaking in Evapo-Rust they come out like new. The stuff is supposed to be only for removing iron (rust) but it works on connector terminals as well. Maybe there is something else that is more appropriate?
What you are thinking of, surface mounted device.
Have you tried to go through all the ground points and check them? Is there a ground point on the intake manifold anywhere?
What about the terminals? You can restore them by soaking in Evapo-Rust they come out like new. The stuff is supposed to be only for removing iron (rust) but it works on connector terminals as well. Maybe there is something else that is more appropriate?
What you are thinking of, surface mounted device.
Have you tried to go through all the ground points and check them? Is there a ground point on the intake manifold anywhere?
I didn't know about that Evap-O-Rust trick but I may give it a try if needed! I have used that stuff to restore cast iron exhaust manifold parts. I never thought to use it on old wires.
Surface Mounted Device. Okay. I just had not connected the industry term to the object it describes. Thank you!
I have gone through all the engine bay ground points and tested them, yes. The 2JZ-GTE intake manifold has two factory ground points coming from the engine harness. I never got bad readings from either of them. Then there is the engine block ground wire to the battery negative, battery negative to chassis/frame and also a small factory transmission ground wire. And I think there is also another engine bay ground point at the back of the engine on the firewall but I have to check what that leads to. Everything with my engine swap was installed according to factory specs but there are so many notes written down that I need to review occasionally.
I am still going to kill two birds with one stone for both the high output upgrade alternator and better grounding with the set of Big 3 2/0 gauge cables soon. I hope they will help in addition to providing good current flow for the incoming alternator.
.....
Side note: tonight I pulled out my very first igniter (which I blew out a while back when this issue first came up). This was a used one with the early style part number but it looks and works the same as the current part number. I popped open the non-servicable lid and peered inside.
Very interesting design. And there is no way to fix one of these. That smudge you see in the middle was where my finger contacted a pool of super clear Jello-like gel that covers all the circuitry. It stuck to my finger like taffy for a moment before springing back into place. I washed my hands with alcohol and then Fast Orange, not knowing if it was toxic or not. But that covers everything electrical in there completely. I assume it's a heat conductive or insulating gel that changes consistency when the circuitry becomes hot.
This one is the first generation 1990's era 89621-22020's. I don't know if the internal design of the updated current version 89621-22030 (which is externally identical) is different in any way but I doubt it. There's nothing to do for this dead igniter. I just wanted to share what one looks like inside.
It's not related to this problem I'm having but it's also interesting to note that both igniter part numbers are used not only for 2JZ-GTE Non-VVT-i and 1JZ-GTE Non-VVT-i equipped Toyotas but also for the 1994-2000 model year MCX10 Toyota Avalons.
![](https://cimg5.ibsrv.net/gimg/www.clublexus.com-vbulletin/2000x1504/e6b61318_9938_4b06_af3c_aa48a1cf4161_4657406d1c3a77c10397b3a23ad740ac43526d2e.jpeg)
Last edited by KahnBB6; 11-23-20 at 11:53 PM.
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LeX2K (11-24-20)
#944
Lexus Fanatic
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Why are those transistors exposed like that? Last time I saw that is when I ripped the cover off of a TO-3 transistor they look like this:
![Kahn's USDM 2JZGTE swap thread (aka The "Not Easy" Way)-bn2c2uy.jpg](https://www.clublexus.com/forums/attachments/build-threads/486982d1683150059t-kahn-s-usdm-2jzgte-swap-thread-aka-the-not-easy-way-bn2c2uy.jpg)
That goo is no doubt to keep moisture out wonder what it actually is, silicone gel? Eat some and find out! No don't do that. Having the Avalon as another source is great.
![Kahn's USDM 2JZGTE swap thread (aka The "Not Easy" Way)-bn2c2uy.jpg](https://www.clublexus.com/forums/attachments/build-threads/486982d1683150059t-kahn-s-usdm-2jzgte-swap-thread-aka-the-not-easy-way-bn2c2uy.jpg)
That goo is no doubt to keep moisture out wonder what it actually is, silicone gel? Eat some and find out! No don't do that. Having the Avalon as another source is great.
#945
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
Why are those transistors exposed like that? Last time I saw that is when I ripped the cover off of a TO-3 transistor they look like this:
That goo is no doubt to keep moisture out wonder what it actually is, silicone gel? Eat some and find out! No don't do that. Having the Avalon as another source is great.
That goo is no doubt to keep moisture out wonder what it actually is, silicone gel? Eat some and find out! No don't do that. Having the Avalon as another source is great.
I'm certain that eating any of the goo could do me some serious harm. I won't be doing that
![Wink](https://www.clublexus.com/forums/images/smilies/wink.gif)
...
Some good news: Since I could only find records on SF of one other person who had this recurring igniter burn issue there hasn't been a lot to go on. But thankfully someone showed up who remembered that saga for the SF member.... and what the culprit was.
https://www.supraforums.com/threads/...#post-13931828
Originally Posted by Suprafied
Scott's (The Pikey's) issue was a result of a bad coil. He went around and around on this from my recollection that resulted in changing turbo kits to everything vs. swapping a set of coils in from another car. If you haven't I would start by getting Denso replacements from Rock Auto or Amazon (Same as OEM with teh "toyota" logo machined off).
After trying many other things the last couple of times it happened to me this is was what everyone has been suggesting could be the real cause. It is the one set of components I had not thought of replacing (other than one quick test with a used coil set a while back with unknown mileage on them... which I have long since sold off). I did not consider replacing them early on with this issue because they were purchased brand new (Denso brand) from a reputable supplier.
Now I have some real confirmation that this issue has probably been due to a damaged or defective coil pack all along. After looking at that Delphi instructional video a few posts back my guess is that it has a slight short that only becomes an issue when the engine is running harder under load... which is probably when it begins doing damage.
In addition to getting new coil packs, new spark plugs and a new igniter installed I'm still going ahead with the 6-phase alternator and "Big Three" upgrade. I think that's good to do anyway.
The last thing is to determine if my current or other two ECUs have in any way been damaged as a result of the bad coil pack in the same way the igniter has been. Hopefully not. I'll start by opening up ECU #1 and inspecting its boards, especially the ignition driver MOSFETs.
Last edited by KahnBB6; 11-27-20 at 03:26 AM.