Turbostar

Try Josh Beaumont @ Relentless Motorsports for the ECU repair

RudysSC

I reached out to Tannin and since they don't have a test vehicle they weren't comfortable offering the repair (which I completely understand). I'll start with coils and plugs and if I continue to have issues I'll reach out to both SIA and Relentless. I sure appreciate it you guys!

The more I drive it the more scared I get that it could be my TB. It went into a no CEL "limp mode" again this morning on the way to work. I turned her off and back on and boom I had pedal again! We'll see. I dread looking for another replacement VVTI throttle body, and if that's the case, it may be time to sell the Cressida and finally order up a plug and play ECU Masters black for this thing...

RudysSC

Well - I (THINK?) I have good news lol. I went ahead and threw some fresh NGK copper plugs in, new denso coils, and new NGK plug wires. I did plugs when I did the swap but decided to retain the old coils and wires for a bit. I'm glad I swapped everything out, this thing purrs like a dream machine.

Now with the TB issues - I went ahead and disconnected the battery to reset the ECU. I plugged everything back in and performed the TB reset procedure (key on - hold pedal down for 30 secs) - and proceeded to drive the car. I've driven it for a few days with no problems, hiccups, or hesitation whatsoever. In the long term standalone, MAP/IAT sensor conversion, and a mechanical throttle body are definitely on my list. However, I'm hoping that this set up can last me as-is for another year or two. The car drives so well and I'd like to avoid spending too much on it for another season or two if I can help it.

Fingers crossed - drove it into work today and my god this car never disappoints. I truly love this thing. Thanks for your guys' input and keep your fingers crossed for my little old TB, HA!

KahnBB6

iTrader: (5)

Rudy, I'm glad you had some recent success! In the very long term it might indeed be good for you to invest in a standalone setup. At local tuning shop near me a few weeks ago I came across a running GS300 with a 2JZ-GTE VVT-i Aristo engine swap. That same VVT-i throttle body was there but the car had just been tuned to run on a Haltech ECU by the shop. They were only just working out the kinks with it. I mentioned the concern with the throttle body to the owner standing next to it but he said it was no longer an issue with the Haltech computer.

For whatever that may be worth to you I'm just passing it on.

I'm picking up my new OEM Non-VVT-i igniter tomorrow which I hope will squash my own recurring ignition hiccup issues for good but I think I may be coming around to the decision that I'll send my original untouched 2JZ-GE engine harness that came with my car off to Tweak'd Performance and have them make a $2k harness for my setup.

With a swap project car it's always the last few fine tuning details that can cause the biggest headaches for long term enjoyment.

Either way we're both kind of at that same final working-it-out stage with our SC's

RXRodger

iTrader: (2)

It is so good to see guys talking on here about spending time working on these machines. Kind of jealous. My race car has been in the trailer since late October, the red car has been sitting in the garage neglected, the white one just gets driven miles and miles with no love. Too many other life irons in the fire to work on any of them. Keep up the good work and keep the reports coming.

KahnBB6

iTrader: (5)

Rodger, you'll resume work and play with your SC racecar when the time is right

It's not all easy on the other end of the forum posts either. My SC has been getting more little fixes since early January and has mostly been sitting (other than periodic startups) while I wait on more parts to come in. And then I've had to deal with a surgery (which I'm healing from just fine now) and some things to help family and plenty of other "irons in the fire" as you put it that all take priority over the classic car.

Give it some time and you'll be back into that driver's seat again : )

RudysSC

Thanks for the comments you guys! Craig - I think you're absolutely right. At some point in time we I have to remember this is a 30 year old car with a 20+ year old motor in it. There comes a time when you have to "get with the times" and that may be on the docket sooner rather than later for both of us especially when it comes to the electrical systems and engine management on these cars. I've got my fingers crossed yours go well so we can both enjoy these bad boys with the nice weather coming in quick!

Roger - sorry to hear you haven't had a chance for any SC therapy. I've been missing your car/race updates and hope to see more of it this year sooner rather than later!

KahnBB6

iTrader: (5)

Same for missing Rodger's SC racear updates! I always love reading about those exploits!

Rudy-- I'm still holding out with my stock ECU system and stock twins to remain with my CA emissions legal goal...but over the very long term I will at least acquire the parts needed to do a simple single replacement with aftermarket management just as a contingency.

In the shorter term I may begin looking into the potential of buying another newer car for primary use to allow the SC to not always be used for every single thing. Way too early for me on that yet but I've been thinking about it.

RudysSC

I will say Craig that having my SC as my "side piece" is truly a blessing. I would daily drive my SC4 but it was MUCH more factory that my current SC3. This car is now so modified that you just can't rely on it like you can a stock car anymore. Having a nice little daily will definitely make your life easier when the time comes. I'm grateful to have my faithful old Tacoma for that reason.

KahnBB6

iTrader: (5)

This has been my thinking as well. And you knew from all my posts that I've had troubles keeping my VERY modified SC300 reliable as a "drive it anywhere and forget it" car. My challenge was to try to prove that this CAN be achieved so long as I were to keep the engine system and wiring all stock. In practice though there have been many challenges. So I think I am coming around to thinking of this as my occasional use classic car when the time comes.

Yet I love a RWD manual transmission two-door coupe that really communicates to the driver (as our SC's do) so it would have to be able to fill those specific shoes even if it doesn't have the timeless turbocharger whoosh. Brand new there's the GR Supra 6-speed manual of course but more realistically the GR86 which, if one can find a near MSRP deal on one, is far more affordable and replicates some practical qualities of the SC300's 2+2 coupe layout. Non-boring used car options are several as well.

It's something I am looking into. I'd love to do what Barbary does with his SC400 but just the same as you I'm a bit leery of the notion of driving everywhere in a 2JZGTE swapped SC. Not to mention.... the fuel economy is terrible on long drives anyway

RudysSC

You Cali guys sure do make me jealous sometimes... I love the idea of my daily being a little RWD coupe, but man, the weather out here sure makes that hard! I also do enjoy having the truck for summer camping, taking the dog around town, etc. Otherwise I'd probably try and daily an older Miata with studded snows all winter LOL. A manual GR Supra is definitely on my attainable dream car list, but I don't have the means to pull the trigger on something like that just yet. However, I've heard wonderful things about the GR86 and sure like the idea of that as a simple fun daily!

I agree - to be completely honest I wouldn't hesitate to take mine as it sits. However, there would always be a "you MIGHT have to tow this a LONG ways home" if something on the VVTI motor fails that isn't available at auto parts stores in the back of my head lol.

Regardless - I sure do love these damn cars. I try to remind myself that we're kind of reaching that "hot rod point" in our lives. Most of the cars I truly lust after are older now and I have to accept that with their age these are "fun cars" and are no longer very practical means of regular transportation without a fair amount of tinkering. That's ok - I wish I could go back in time and tell 16 y.o. me that I'd be doing donuts regularly in a turbo 2jz car.

KahnBB6

iTrader: (5)

Rudy-- Same!!

Yeah, I think these cars are certainly at the "hot rod" point by now. I mean... look at what the majority of us do with these older SCs. Certainly we don't leave them stock. Even JZZ30 Soarer owners don't leave their cars stock.

I love my SC a lot. It's a car from an era of design and engineering that is not really offered any longer in this fashion. But... I am now leaning in the direction of getting another newer car as a daily. After all my recent troubles (ongoing sadly...) I think I may finally entertain the idea of going with a single turbo and aftermarket ECU + harness.... *IF* a proven and reliable setup that doesn't have my same issues is possible. But then this also means that I would not be able to register my SC back in California. Which also means it would only be driven when I am in Florida. If I leave it as is and can just pinpoint the issue then it remains possible to register back in CA again... but with these somewhat iffy old engine electronics.

Not everyone faces such a scenario with their SC.

Aside, Rudy the last few years as we have gotten to know each other I have been in Florida with my SC. It's just that I set it up to pass CA BAR inspection and smog so as to be able to bring it back with me when I move again. So far that hasn't happened yet but all the required configuration and work has been done. So if it *did* get presented to them in its present setup it would be almost guaranteed to pass.

Now if it only it weren't for the Igniter and ECU issues and very old turbo waste-gates...

RudysSC

Craig (facepalm) - I forgot you've been in Florida all this time! I couldn't agree more. It'll be challenge moving forward to keep these cars reliable and road worthy but I don't see a scenario in my head any time soon that I'll be getting rid of mine.

HOWEVER, LOL - the car did act up again this morning. Chillier morning (probably about 30 deg F outside when I left my house). I let the car warm up fully (my drive to work is only a few highway miles so I always give it time to warm up before I leave) and headed out to work. Once I went to get onto the highway I lightly rolled into the throttle and BAM - another hesitation issue as I start to roll into the throttle (it happened before any positive boost/manifold pressure was built). It almost feels like it's breaking up - not like the throttle body is closing, but more like it's stuttering/missing). If you stay in the throttle it'll either clear out and keep accelerating, or, hit another point in the rev range where it'll start to hesitate/miss again. It continued to do this all the way to work and once I got closer to work and the car was at full operating temp it promptly stalled as soon as I'd push in the clutch and let off the throttle. It did this twice and as I re-started the car it began to idle VERY erratically.

No CEL on (typically it will light up the CEL even with the stock VVTI Supra ECU when it goes into limp mode - which it did NOT do).

**** guys - I'm at such a loss since I can't pull any codes from this thing. I've been thinking it could of course be the throttle body, however, now I'm leaning more towards either a intermittent sensor failure (MAF, MAP, or perhaps temp), a vacuum leak, or I also saw a few threads of the Supra forum mentioning the possibility of a clogged VVTI screen (but that doesn't seem to make sense in this case). It's got a fresh set of plugs, coils, and wires which have apparently not changed much of anything lol.

I'd love your guys' input... Any thoughts?

silentkill

Standalone would fix all of your issues Rudy 😇

Standalones just need crank and cam signal to run 😎

RudysSC

I know... I KNOW ALL TOO WELL LOL.

I'm hoping I can get it through the year and enjoy it as-is. If not - I'll be going with an ECU Masters Black (since they offer the VVTI plug and play), switch over to speed density, and will be living the good life lol.