Slayer Posted October 29, 2020 Author Share Posted October 29, 2020 Hi, Engine my supra currently sit on around 3.5k when I am doing around 85 mph... Various forum members suggested the capacitors in the ECU need replacing. Does anyone have a spare ECU for sale ? I am thinking to have capacitors replaced, so would like to buy one to confirm it is an issue before I send it off for repair. Does anyone know the part number please? Is it the same as a JDM auto pre-vvti? Thanks. Link to comment Share on other sites More sharing options...
Burna Posted October 29, 2020 Share Posted October 29, 2020 It's not the same as the JDM ecu I'm afraid Link to comment Share on other sites More sharing options...
Slayer Posted October 29, 2020 Author Share Posted October 29, 2020 [quote name='Burna']It's not the same as the JDM ecu I'm afraid[/QUOTE] So my only option is to get it fixed somehow or get a UK spec Auto ECU? Link to comment Share on other sites More sharing options...
Burna Posted October 29, 2020 Share Posted October 29, 2020 [quote name='Slayer']So my only option is to get it fixed somehow or get a UK spec Auto ECU?[/QUOTE] That is correct I'm afraid. Link to comment Share on other sites More sharing options...
and1c Posted October 31, 2020 Share Posted October 31, 2020 Whats the part number for this guys? I may have one on the shelf Link to comment Share on other sites More sharing options...
Slayer Posted October 31, 2020 Author Share Posted October 31, 2020 [quote name='and1c']Whats the part number for this guys? I may have one on the shelf[/QUOTE] Part number is 89661-x46xx, can't really read it out. Could someone provide the part number? Photo of my ECU attached Link to comment Share on other sites More sharing options...
Dnk Posted October 31, 2020 Share Posted October 31, 2020 [quote name='Slayer']Part number is 89661-x46xx, can't really read it out. Could someone provide the part number? Photo of my ECU attached[/QUOTE] here you go Link to comment Share on other sites More sharing options...
Slayer Posted October 31, 2020 Author Share Posted October 31, 2020 Thanks, much appreciated. I thought someone mentioned JDM and UK spec not interchangeable ? So I need ECU with part mumbrt 89661-14661 - this is specific to UK spec only ? Would the EU spec have the same ECU? Surely Toyota would not have designed a different ECU just for the UK market ? Link to comment Share on other sites More sharing options...
and1c Posted November 1, 2020 Share Posted November 1, 2020 Sorry, just checked. THe one I have is 89661-14660 which I believe is the Pre vvti jspec ecu :/ Link to comment Share on other sites More sharing options...
Slayer Posted November 1, 2020 Author Share Posted November 1, 2020 [quote name='and1c']Sorry, just checked. THe one I have is 89661-14660 which I believe is the Pre vvti jspec ecu :/[/QUOTE] Actually mine is 1995 which is pre-vvti. So 2 different ECU part numbers for pre vvti auto supra? So one is JDM and the other UK spec ? Link to comment Share on other sites More sharing options...
blythmrk Posted November 1, 2020 Share Posted November 1, 2020 As Burma previously stated the U.K. ecu’s are different. Not sure on either EU spec or possibly US SPEC may fit but I would only go with the matching part number one. Link to comment Share on other sites More sharing options...
snuf Posted April 5, 2021 Share Posted April 5, 2021 On 10/29/2020 at 12:45 AM, Slayer said: Hi, Engine my supra currently sit on around 3.5k when I am doing around 85 mph... Various forum members suggested the capacitors in the ECU need replacing. Does anyone have a spare ECU for sale ? I am thinking to have capacitors replaced, so would like to buy one to confirm it is an issue before I send it off for repair. Does anyone know the part number please? Is it the same as a JDM auto pre-vvti? Thanks. My 1995 uk spec TT Auto. ecu part number is 89661-14661. (They are very rare). There’s one on eBay. Good luck snuf Link to comment Share on other sites More sharing options...
Slayer Posted April 6, 2021 Author Share Posted April 6, 2021 Thanks for the info snuf. so you have a UK spec 95 Supra auto as well, have you done any modifications? I spoke to SRD about it and was told that it is normal, because it is a 4 speed auto box, it would sit in a higher rpm compared to a manual. at a speed of 85mph, what is your engine rpm reading ? Thanks Slay Link to comment Share on other sites More sharing options...
chaoticentity Posted April 6, 2021 Share Posted April 6, 2021 (edited) 21 hours ago, Slayer said: Thanks for the info snuf. so you have a UK spec 95 Supra auto as well, have you done any modifications? I spoke to SRD about it and was told that it is normal, because it is a 4 speed auto box, it would sit in a higher rpm compared to a manual. at a speed of 85mph, what is your engine rpm reading ? Thanks Slay Quick bit of calculations but when in overdrive 85mph leads to about 3k rpm. 85mph in 3rd gear leads to 4k rpm. That's with a 265/35/r18 tyre. I've got a UK spec 93 auto. Gear ratios are as follows: 1st gear 2.804, 2nd gear 1.531, 3rd gear 1.0, overdrive 0.753. The diff ratio is 3.266 3.538 Edited April 7, 2021 by chaoticentity Got the wrong diff ratio (see edit history) Link to comment Share on other sites More sharing options...
Slayer Posted April 6, 2021 Author Share Posted April 6, 2021 That is what I thought as well... not on overdrive when I was doing 85 mph, but I was able to disengage overdrive and rpm went even higher, which means I was actually on overdrive gear. one thing I could think of was that I went from stock wheels and tyres to 35/19 , which would have caused an issue on odometer reading, but should not have caused this kind of discrepancy. so I am not really sure what exactly is wrong with it, if I am indeed losing a gear? Link to comment Share on other sites More sharing options...
Swampy442 Posted April 6, 2021 Share Posted April 6, 2021 If you think you have an issue, pull the gearbox error codes, that will tell you if you have a duff solenoid Link to comment Share on other sites More sharing options...
Scooter Posted April 7, 2021 Share Posted April 7, 2021 11 hours ago, Slayer said: so I am not really sure what exactly is wrong with it, if I am indeed losing a gear? At 70-85mph, what does your overdrive button (the lower down smaller button on the inside of the auto shifter) do. As long as you are not in manual mode pressing this in and out will shift you between 3rd and 4th and obviously you'll see the rev's change. So check/press "Manual" mode button does give a light up on the dash, if yes, then turn it back off. Get to 70mph driving slowly, the car should then be in fourth, press the overdrive button, you should get a dash "Overdirve off" light and the revs should increase as the gearbox drops to 3rd. It'll then rev out so get to say 85 and then press the button again and it should go into 4th and the revs drop. If it does all this ok then the gearbox is doing what it should. If the revs are high then it's looking at diff's and tyres (note generally tyre combo's if anything make the gear ratios longer ie are large rolling radius than stock so unlikely to be that giving you higher revs at a certain speed) Link to comment Share on other sites More sharing options...
Slayer Posted April 7, 2021 Author Share Posted April 7, 2021 Thanks Scooter for the information. I did try what you suggested and gearbox appears to be shifting as expected. So does this mean that I may be looking at diff's issue, how could I check this? I did also try and pull the error code using the diagnostic port, but there was nothing. Thanks for the help. Link to comment Share on other sites More sharing options...
Scooter Posted April 7, 2021 Share Posted April 7, 2021 Ideally another uk owner could compare speeds/rpm's You can jack up the rear and in Neutral rotate the propshaft/wheels and work the ratio out that way? From the link below it looks like a standard UK auto will be as near as damn it 3.5...... https://www.supraforums.com/threads/jza80-differential-info.608545/ Link to comment Share on other sites More sharing options...
chaoticentity Posted April 7, 2021 Share Posted April 7, 2021 3 hours ago, Scooter said: Ideally another uk owner could compare speeds/rpm's You can jack up the rear and in Neutral rotate the propshaft/wheels and work the ratio out that way? From the link below it looks like a standard UK auto will be as near as damn it 3.5...... https://www.supraforums.com/threads/jza80-differential-info.608545/ I got the wrong diff ratio above, so I've rerun the numbers. 3k rpm for overdrive @ 85mph or 4k rpm for 3rd gear @ 85mph Link to comment Share on other sites More sharing options...
Slayer Posted April 9, 2021 Author Share Posted April 9, 2021 Thanks for the numbers... maybe I am not too far off then, so it is probably normal to have the engine rev at 3k doing 85mph. i guess this is the same for jdm model as well. Link to comment Share on other sites More sharing options...
chaoticentity Posted April 9, 2021 Share Posted April 9, 2021 6 hours ago, Slayer said: Thanks for the numbers... maybe I am not too far off then, so it is probably normal to have the engine rev at 3k doing 85mph. i guess this is the same for jdm model as well. Using Grannas Racing as a source for information on the diff ratios -> JDM autos either had 3.769 or 4.083 rear diffs. 3.769 -> 85mph @ 3.2k rpm in overdrive, 85mph @ 4.3k rpm in 3rd gear. 4.083 -> 85mph @ 3.5k rpm in overdrive, 85mph @ 4.6k rpm in 3rd gear. Calculated with 265/35/r18 rear tyres Link to comment Share on other sites More sharing options...
snuf Posted April 11, 2021 Share Posted April 11, 2021 On 10/29/2020 at 12:45 AM, Slayer said: Hi, Engine my supra currently sit on around 3.5k when I am doing around 85 mph... Various forum members suggested the capacitors in the ECU need replacing. Does anyone have a spare ECU for sale ? I am thinking to have capacitors replaced, so would like to buy one to confirm it is an issue before I send it off for repair. Does anyone know the part number please? Is it the same as a JDM auto pre-vvti? Thanks. If engine revs=3.5k and speed is 85mph, then this appears to be ok. If you think about it at engine revs=7k then speed would be doubled ie: 170mph. Link to comment Share on other sites More sharing options...
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