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I'm sure we are all relived and happy you are doing 100% better. I'm sure you were in all our thoughts, but sorry for your ordeal. Yes, health is wealth
On this 2nd part, maybe you are right. My thought has come to be, just mine, may be 100% wrong. The more things you change, the more you add, modify, the probability something goes wrong goes up. So there is that probability and does one want to drive around w that probability in the back their mind?
Simply put....the more things you add, the more things can go wrong. but it's hard to give up the ghost
Like I said thats just me
I for one would be curious what your much newer car turns out to be
Thanks Joe!! I'm very grateful and glad to have been able to get it done. It's been a year-long thing up to this point but now the worst is behind me. Health it definitely wealth as you say
I generally agree with you regarding the reliability of a car that has been extensively and heavily modified. But since this swap is so close to a stock configuration (just swapped into another similar chassis) I had hoped that it could be considered a reliable "go anywhere" car so long as I rebuilt and reconditioned as much as I possibly could. I made a few minor but nonetheless crucial mistakes which I have had to correct. Even this Supra Twin Turbo Fuel ECU failure is a fairly common thing with MKIV Supras. My string of Igniter failures... that was a pretty rare phenomenon.
I guess that the naturally aspirated 2JZ-GE and 1UZ-FE, both being less complicated overall, still win out in the long hauler reliability metric. Maybe counter-intuitively a slightly more modified 2JZ-GTE or 1JZ-GTE which isn't sticking to only all antique discontinued Toyota electronics would be nearly as reliable? Hard to say.
But any car with sufficient age (especially one that's 30 years old) and harder than normal to find parts begins to test any owner's assessment of its ability to do long haul driving.
...
I'm curious about what I'll get into myself. Used not much appeals to me-- I already looked into every notable and interesting model back in 2010... and the SC300 5-speed was what I ended up with, not fully realizing just how far I would go with it.
I absolutely won't get into any automatic vehicle. Manual only. It's too much fun not to drive a manual and the time to enjoy one is now.
Looking around right now... I'd perhaps look into 2008-2013 Infiniti G37 6-speed manual coupes because they more or less approximate as a newer replacement for what an SC300 5-speed is with more horsepower and torque standard... but they are very difficult to locate in 6-speed manual.
Money no object I'd consider the new manual Supra but more realistically I'm considering one of the GR86 manual cars... with BRZ Performance Pack Brembo brakes swapped on with all the factory trimmings for an OEM finish. They're 2850lb 2+2 rear-drive manual coupes with a standard Torsen T2 LSD that have sublime driving characteristics and decent enough daily practicality for me. And the engines seem to be underrated: They're advertised at an official 228hp but on dynos it has been revealed that their little 2.4L boxer engines are putting out closer to 245hp at the crank with much more torque and a far more usable powerband than the previous generation.
Plus the GR86 is just beautiful! So is the Supra MKV but it also costs twice as much as the 86
Any of Toyota's GR vehicles are a real pain to find and buy new for reasonable money but that one in particular has my eye as a practical daily go-anywhere car that is fun to drive like the SC is.
My SC stays of course but it will be better for it to become a secondary car.
Well... I'm currently at a loss. I may just take my SC into a local performance shop to have them look at it when I can afford to get it towed over there.
I got back from a long trip tonight (using a rental vehicle) and decided to give the SC a try again since I'd had the battery topped off on a trickle charger.
It fired right up! No need to jump FP & +B to bypass the Fuel ECU at all. I let it idle and warm up to temperature, gave it a few revs and rolled it forward and backward in 1st and 2nd. Everything was perfectly fine and smooth. I was going to leave it at that and just as I came around from the engine bay to walk back to the driver's seat I noticed that the sound of the engine was much quieter by the time I reached the door.
It had just shut itself down on its own.
SO.....
Then I tried restarting-- slight crank but it wouldn't hold into an idle. I inserted jumpers into FP & +B and this time.... still no change. Yeesh!
This was with my brand new OEM Igniter and my fourth 6-speed ECU which has not had capacitor service yet but which was in good working condition last I started the car and tested with it.
I guess I'll re-test all the other ECU's one more time and will swap out that Fuel ECU with my spare one after all... or just go with the +12V Mod + Relay + SC300 Fuel ECU as a safety trigger.
But at this point I think I'm just getting overly worn down and stumped with this issue. Maybe I will just keep it as a Florida only car and forget the strict CA emissions compliance regimen. And maybe the only way to truly get this thing reliable again is to go with a standalone ECU.
Maybe a Link G4X or Haltech or ProEFI. I am in no way qualified to fine tune the car with one of those however. Also... I think that such an ECU system is totally overkill for what my power and everyday usability goals have been with this thing.
Further, if the SC is left in Florida it will increasingly not be driven much at all after this year even if it's totally dialed in again. Not if I've moved and can't take it with me and register it. That brings up long term storage implications.
A bit frustrating all around. For all the work I have done to this SC to get it near perfect I am at the moment just burned out and stumped with this ignition cutout mystery. Other than the testing mentioned above I have run out of other ideas other than to go standalone and abandon the 100% CA emissions legal goal. Maybe it's the four hours of sleep fumes I've managed to run on all day that is doing my talking for me right now.
I am just thinking out loud here but I'm just amazed at this latest string of results. I am baffled and quite frustrated.
Bottom line... the ECUs, MAF and Fuel ECU are all quite old electronics. I always seem to get the worst luck with this car when trying to fix these weird issues. In contrast the modifications and hardware installations always go perfectly! I'm very happy with how the car has turned out after all the work I've put in!
Tuning is not something I am at all qualified for so if an aftermarket standalone ECU turns out to be my direction then I will be in all new and unfamiliar territory. I've seen examples of it being done but seeing and having experience doing are two very different things.
Also I'm not so sure if even a standalone ECU can be accurately programmed to replicate the factory EGR function (yes, I'd still keep it if possible) and sequential twin operation functions and logic. I know that some have set up their Link ECU's to work with stock sequential twin turbos but it's not commonly done. I'm cautious about how well the finer aspects of Toyota's and Hitachi's hard coded fuel maps and programming can be reverse engineered.
...Which of course introduces the more common solution of going with a modern single turbo with good spool characteristics.
...Which then contradicts one of the main reasons I did this swap in the first place: to do it all the OEM Toyota way and keep the engine system "stock", "reliable", "simple" (hahaha...!) and adaptable to ALL normal road conditions and scenarios.
...
Lots of thinking for me to do here. Perhaps I am only missing some very minor detail which I have overlooked at the moment... or maybe I do need to consider a change in the long term build configuration and use of the SC.
...But first I'm going to get some good sleep. I will make no progress without rest and a clear mind
Sounds like you and I both need a fresh set of eyes on our cars before we get too carried away with parts swapping...
I will say - on the note of going standalone. I've been down that road twice now with two different cars in my 2jzge vvti swapped cressida and my k20z1 civic. I used MS3 pro on the cressida and it was phenomenal. I had to build a harness to use it (our cars have the luxury of having plug and play set ups), however, the functions that these new standalone ecu's have is truly spectacular. They can do everything from basic engine mapping, vvti tables, egr functions, traction control, and so much more. The trick, however, is to find someone ahead of time familiar with THAT ecu and their software (a little familiarity with your engine is of course a necessity as well). You'll spend a pretty penny on having that person get you set up, however, both of my experiences were incredible. The cars drove and functioned unbelievably well an the money I spent to have a knowledgeable person get them set up properly was worth every penny.
Moving forward, if you go that route, you'll spend a few bucks absolutely. However, I promise you if it's set up and tuned properly it'll run better than you'd ever imagine.
Rudy-- I agree. I've been under other pressures lately with little available time to stay with testing efforts to correct the problem quickly. However a standalone is a consideration for me now if it will eliminate some of these issues.
But also going in that direction would potentially make for a drastic change in the usage intention of my SC going forward. And maybe that's okay if it gives an overall better driving experience. Looking ahead into the next several months I was already not planning to use the SC as my primary car anyway so maybe it's just one of those developments that cannot be avoided and which must be adapted to.
A standalone and high quality in-depth tune and other little changes needed to support this aren't something I could do right now even if I decided to but just like you I am considering it.
This would also finally violate my entire original reason for starting this build thread (the 100% by-the-book CA emissions passing 2JZ-GTE configuration) so I'm on the fence for that reason as well. But perhaps it was a good fight and the knowledge documented therein has ultimately been of more help to others who were able to get their CA-legal GTE swaps done and CA BAR inspected and certified faster than I could.
I've got the rest of the testing between ECUs and Fuel ECU (and bypass) setups to get through before I cross that bridge.
I totally understand! You and I are in similar boats right now that's for sure. Some days it makes me miss the simplicity of an N/A car with a working OBD1 scan procedure lol.
I totally understand! You and I are in similar boats right now that's for sure. Some days it makes me miss the simplicity of an N/A car with a working OBD1 scan procedure lol.
I N/A certainly can be easier to diagnose, at least with this stock turbo system. I think that a single turbo setup and modified fuel system is probably much easier to pinpoint problems with. I do have the benefit of OBD1 code diagnosis with the blinking CEL light patterns but in practice it only really helps in certain circumstances.
With my Igniter burning saga I get little more than "Code 14 Bad IGF" which could be anything from the Igniter unit to a bad coil pack to a faulty ECU and anything in the wiring path for that entire circuit.
Early OBD2 might be a little more specific with diagnosis codes. It's just harder to do swaps with and has more things that can be flagged when you change things in the engine configuration.
Japan OBD diagnosis I have no experience with but yeah, if you have no scanning hardware for it to be able to pull even the most basic of codes things can become very confusing very fast. Is there no such scanner that you can buy, Rudy?
Some progress tonight but I don't yet truly know how much it all helped.
Last night, same as tonight the car would start right up again into Closed Loop and get up to temperature. The last random shutdown I experienced a couple of days ago was only after I had let the engine fully warm up to operating temperature for quite a few minutes and then revved it a little in place. Only then did it have trouble restarting. This was still while using my fourth and not capacitor serviced ECU.
Tonight, still using the brand new OEM Toyota Igniter and the fourth not-cap-serviced ECU it started right up from cold. This time I didn't let it sit for 15-20 min at idle but I had zero issues with it coming to temperature and revving a little before I shut off the ignition myself.
...
I ran another Ignition ON (but no start) FP & +B test of the TT Fuel ECU and all functions worked correctly.
Nonetheless I wanted to see what would happen by trying my spare and I wanted to inspect the TT Fuel ECU that I have been using since 2018. I can still re-wire the system for a 12V Mod w/Relay & SC300 Fuel ECU as the safety trigger/shutoff but first I just wanted to see if using the spare TT Fuel ECU made any difference at all.
I removed the first TT Fuel ECU, swapped in the 2nd spare one and just because I was in there with the back seats out I also pre-emptively replaced the generic aftermarket 30/40A relay that I have hooked up in that location which serves as my "Supra MKIV TT EFI2 relay". The 30A fuse for this is in the engine bay in a separate Littelfuse power distribution box.
....
Then I moved to the engine bay and opened the fuse box. For a long time I have not liked the slight corrosion on the critical areas of my 120A Alternator Fusible Link and the 100A AM1 circuit's Fusible Link.
So I replaced both of those with brand new OEM spares that I have had for a rainy day. At this point it cannot hurt I figure.
Unfortunately I mixed them up but both part numbers from Toyota/Lexus are: 90982-08270 and 90982-08271
I also installed a brand new OEM EFI Main Relay. Again, at this point it cannot hurt to have a brand new one installed after the old one has probably done 30 years of service. That is P/N 90987-02004-83.
.....
So with all of that and a topped off battery thanks to my Battery Tender I gave the SC a start with all these components replaced but still using the new OEM Toyota Igniter and the fourth ECU (no service to its capacitors yet).
Just as before the engine came on and idled well. No issues. I cut it off after a few minutes myself.
These are good results so far. I will get into re-testing with each ECU tomorrow or another day.
....
Maybe one of these minor component replacements has done some good or maybe all my ECUs are just in various states of wear and tear. And maybe at current time something about all of this is related to an electronic component coming up to a certain temperature before it has an issue.
Very hard to say but I'll see what happens with all the other ECUs very shortly.
In the long term it probably would be a good idea to consider an aftermarket standalone ECU as a much more modern and reliable alternative to one of these nearly 30 year old stock Toyota ECUs.
Oh my god Craig lol it's like we're both in bizarre-o world with these things! It's so damn frustrating to have such a horrible problem be intermittent. Sounds like we both have some tinkering to do and I also think we both will need to look into a new-reliable standalone system sooner rather than later.
LOL!! We both know you guys are right... TBH I HATE diagnostics lol - I'd much rather the car spit a code at me, or, on the contrary, an engine simple enough to not need a diag system lol.
My plan right now is to go ECU Masters Black since they do a VVTI plug and play. The system seems very affordable and capable for my needs. I've had more than one car on a well set up standalone system in the past and absolutely loved the whole experience. I've just been dragging my feet mostly because of $$. Although I own my own business, I've been paying myself quite modestly since purchasing it and will continue to do so for a bit (I'm so conservative right now with it - that'll change eventually). However, at this rate, I think I'm going to ditch my Cressida and free up some money to throw at the SC later this year/winter. Get that old girl on speed density, get rid of the e-TB, and just let that baby sing.
Rudy-- Yeah, I think it's at that point for me as well as for you, so we'll need to figure something out for our cars before long as to a standalone. I am also not jumping on it right now due to the cost involved and because I'm also keeping expenses to a minimum this summer to plan ahead for getting a new primary vehicle. But I do think a standalone ECU with modern electronics will ultimately be my solution for my SC as well.
Nick-- Funny you should mention that. I recently came across a local tuning shop that appears to have regular business and a good reputation. At least one of the ECUs they specialize in is with Haltech. I've been to their shop once without my SC and it has been on my list of things to get over there with it and have a conversation about standalone options.
Joe-- A G4X or other Link ECU has been at the top of my potential standalone list. I'm not sure if anyone locally knows how to tune with it well though and the tuning expertise with one ECU system or another is key. But I like what I have learned about their computers so far. Nonetheless I am open to all the options (Link, Haltech, ProEFI 128, etc.).
Hopefully I can make do for now with my Toyota OEM ECUs until such time but for now I am not wanting to make any big changes to the SC until I have found myself another long term and much newer daily driver.
Too bad you're not near me I'd find your problem. Those fuses are not a little corroded they are very corroded they normally look like copper, not copper oxide.
Too bad you're not near me I'd find your problem. Those fuses are not a little corroded they are very corroded they normally look like copper, not copper oxide.
I agree. I've been looking at those fusible links for long enough and finally replaced them with brand new OEM spares that I had in a spare parts bin the other day. I am not sure they were any cause of my issue with Igniters but as you said they should NOT have looked like that. The copper spade contacts that get bolted down were in 100% clean condition though.
If I were near you I'd certainly take you up on that to have another set of eyes more experienced than I on my car's electrical system to find the issue.
At current time the car runs and drives without issue after all my current fixes with my newest ECU acquisition (which hasn't yet had capacitors replaced but which has demonstrated no problems) but I just haven't been driving the car anywhere. I'm too busy with other things to risk dealing with another potential tow back to my house late at night. Even pushing this car in my driveway into a good spot with the engine off isn't easy for me. So for now I'm just averting any of that risk until I can devote some more time to testing it further.
But for the moment... no issues. I'm just being overly cautious and risk-averse amidst my busy schedule.
02-26-23, 11:41 PM
but it's hard to give up the ghost
