Ali - the stop screw is on the passenger side of the TB and goes up and down into it correct? I’ve got it quite a bit down currently, and when I adjusted it the idle didn’t change one bit. I can play with it a little more tomorrow with the TPS adjustment and see what happens!

 

The vvti throttle body will have the throttle position sensor , accelerator pedal position sensor and the IACV control . Sounds like to me the problem is the apps on the TB but that is damn so pricey. Worth finding a complete vvti throttle body so you replace the tps, apps and iacv related stuff. Borrow someone's TB who is local so you don't keep buying parts that might not even be necessary . Then when you are sure , that is the time to buy a TB with all the sensors.

 

Yeah i'm agreeing with Ali and Khan, Its throttle body related i'd bet. IACV idle air control valve if i had to pick a component to just replace. I can come by and help you test stuff if your okay with it during the COVID situation lol

 

^^ The more I have read from Ali SC3 and Gerrb's responses I am in agreement with both of them. I'm used to working with the non-VVTi GE and GTE stuff but the dual mechanical TPS and drive by wire (if I am understanding correctly) is more than likely the culprit. Admittedly I am still very new to all the signals that the GTE VVT-i throttle bodies put out and how they are calibrated.

When my Non-VVTi Idle Air Control Valve was unplugged once at startup the engine did immediately rev to 2k(?) or so RPM immediately but it was not intermittent and did not prevent my revving the engine higher with my mechanical throttle. It was one of my first thoughts as to the potential issue but after much reading since I also think it's related to the VVT-i throttle body.

I also agree with Gerrb's suggestion to buy a used 2JZ-GTE VVT-i throttle body to test with (or take parts from to fix yours) before spending on a brand new one (if still available).

 

I greatly appreciate all of your input and I must agree. I don't think this is ECU related or can be fixed with a simple TPS adjustment, unfortunately. If anyone locally has a used TB they'd be willing to let me try please let me know. Otherwise, Gerry is kind enough to offer a very fair deal on an extra unit he has lying around which I plan on purchasing this week.

Ryan - I'll definitely give you a shout and would love some company and help looking it over to be certain! I appreciate the offer man!

Thank you guys!! I'll keep you guys updated on what I find. This hard to find stock ecu/maf/dbw tb situation is growing old quickly lol. My new long term plan is definitely looking into converting this TB to a manual unit and going standalone. Might be next winter's project...

 

I think you just convinced me to go standalone if I do a vvti setup, I figured vvti stuff was picky but didn't realize it was that picky!
I think if you found a good unit it would probably last a while though, or if you get that bypass thing you could use yours minus the idle stuff.

 

I think going standalone would be well worth the investment. I just don't have the cash to throw at it after completing the swap. Plus, with everything going on, I'm scared to go spending to much money on toys.

However, I hope you're right Ali! If I can get it dialed in and a little more reliable/consistent then I'd like to leave it as is for the foreseeable future. I'd like to try the mechanical conversion for the TB but it sounds like guys don't have very good luck with them on stock ECU's. I wouldn't mind it idling a little strange, but I think it causes more problems than it solves from the sounds of things.

Gerry (being the man that he is) is sending me an extra TB to play with. I'll install and tinker next week and let you guys know how it goes! Ryan (SCsexy) may come by too so hopefully I get to check out his badass NAT set up.

 

I had used heater hose on accident for my remote PS reservoir. The hoses had started to “weep” oil and slowly balloon lol. I went out and replaced these hoses with PS line and re-bled the system. Anyone who has tried to use normal straight hose on this swap for the suction hose knows what a pain in the *** it is to do it without it crimping. So I cut the outlet on the reservoir and my friend silicon bronzed it on a few minutes notice at his shop today (he owed me one lol). Anyway, it made it a straight shot to the PS pump so you don’t have to special order a GTE hose.

Great day to be outside in denver today.

 

Rudy,
I just finished reading this entire thread. It was really fun to read how you bought the car, drove it stock for a while, then finally transplanted a 2JZGTE motor into it. You did a great job documenting the entire journey. Kahn, Ali, Gerrb all contributed a tremendous amout of info and it is great to see this sense of community. I really enjoyed this read. Keep up the great work. I will be following your progress. I sold my SC400 years ago and am now searching for another SC. Your posts are inspiring!
Thanks for a great write-up.
Matt

 

Matt - thank you sir! I'm stoked to hear that you enjoyed reading through. Craig (Kahn), Ali, and Gerry (Gerrb) helped me so much and I hope that others will reference this thread for help on their own swaps! These cars are so great, and it makes me happy to see how they can bring us all together from across the country.

Good luck on finding your next SC - I'm on my second and one way or another always find my way back to one. I hope the same is true for you!

 

Rudy, I have owned a lot of Lexi (if that is actually the plural form of Lexus). Started with a 1990 ES250, then 1992 ES300, then 1990 LS400, then 1995 LS400, then 1996 SC400, then 2000 GS400, then 2000 RX300, 2002 ES330, 2005 RX330 (still in the stable), 2006 IS350 Sport Package (still in stable), and 2015 RX350 F-Sport (still in the stable). Also owned a 1990 4Runner too. No stranger to Toyota. I loved the GS400. It was unbelieveably quick and smooth. But I really miss that SC, so as I mentioned, I am on the hunt. I really love reading build threads like yours. It is awesome to see the transformation. I look forward to more progress on your SC. Thanks!

 

Matt - you certainly are no stranger! I appreciate the compliment and will definitely continue to update this thread as I continue to tinker. Best of luck on your search for another SC!

 

In between SC’s, I owned a killer 1985 Cressida that eventually got 2jzge swapped with a w58 and tuned on MS3 pro. It was absolutely awesome, but I got rid of it in order to get the SC you see in this thread. Long story short, my wonderful girlfriend surprised me for my 30th birthday with an ‘81 that my friend who sold me the ‘85 before I swapped it sold her haha. He sold it to her for $400, it’s a beater, but nearly EVERYTHING works. It needs a ton of work, but parts are wicked cheap and this will make for an awesome little beater to cruise around town with my girls (girlfriend and dog lol).

My ‘85


The new ‘81 (and my dorky self)

 

OK those Cressida’s are wicked! I love the sleeper look of the sedan the with the 2JZ transplant! Those will certainly surprise a lot of hot shot sports car owners at stoplights!

 

I love the old Cressidas myself. MX83’s and the MX73’s (both of those are MX73’s, right?).

Both very nice cars Rudy!! That ‘85 with the GE and W58 must have been tons of fun!

Will you do the same style swap to the 1981 model? That period correct look is actually really nice as is!