Milo500 Posted March 30, 2018 Author Share Posted March 30, 2018 (edited) I'm hoping it's not the box, and it feels exactly the same as the last box, so I presume it isn't. It redlines in neutral but is the same problem in every other gear. I have a sneak suspicion that it is the boost controller, as the screen was smashed about 5 months ago around the time when the gearbox did this, but because it was slipping in every gear badly, I presumed this was it's final blow. I have another controller coming and will see how It goes as I cannot change the boost settings on my current greddy profec. Also I will add, the air fuel ratio peaks extremly rich when this happens. Edited March 30, 2018 by Milo500 (see edit history) Quote Link to comment Share on other sites More sharing options...
mellonman Posted March 30, 2018 Share Posted March 30, 2018 (edited) unplug the boost controller and run off wastegate and see dude , update the thread if you find the problem though also the stock ecu can fail causing gearbox issues Edited March 30, 2018 by mellonman (see edit history) Quote Link to comment Share on other sites More sharing options...
Milo500 Posted March 30, 2018 Author Share Posted March 30, 2018 Ok man will do Quote Link to comment Share on other sites More sharing options...
mellonman Posted March 30, 2018 Share Posted March 30, 2018 just see you say that the afr are really rich when this happens , that would indicate misfire as the fuel is not burn and comes out the exhaust but still need to go one step at a time , Quote Link to comment Share on other sites More sharing options...
Milo500 Posted April 2, 2018 Author Share Posted April 2, 2018 The afrs are rich. I have changed the boost controller, it is fine up to to about 0.9 bar, anything higher than that it starts cutting...usually it is at 1.5bar. Quote Link to comment Share on other sites More sharing options...
mellonman Posted April 2, 2018 Share Posted April 2, 2018 Could be a coil pack / clips if that's the case . So if you run low boost ie 0.7 it's fine and goes to the red line Quote Link to comment Share on other sites More sharing options...
Milo500 Posted April 3, 2018 Author Share Posted April 3, 2018 I always hear this, what do you mean by the coil pack clips? As they are just pencil coil packs right on top of the plugs (non vvti). And yea low down it fine Quote Link to comment Share on other sites More sharing options...
Dnk Posted April 3, 2018 Share Posted April 3, 2018 These Quote Link to comment Share on other sites More sharing options...
Ric Posted April 3, 2018 Share Posted April 3, 2018 Does it have a fuel cut defender? Quote Link to comment Share on other sites More sharing options...
Milo500 Posted April 3, 2018 Author Share Posted April 3, 2018 Does it have a fuel cut defender? No it doesn't Has one built into the piggyback ecu Quote Link to comment Share on other sites More sharing options...
Milo500 Posted April 3, 2018 Author Share Posted April 3, 2018 These Wow that was a dense question I asked haha, even if they were damaged surely it would miss fire all the time, but hwne just on high boost...(is ok at 0.7bar but cuts any higher than 0.9 bar, is usually 1.5bar Quote Link to comment Share on other sites More sharing options...
mellonman Posted April 3, 2018 Share Posted April 3, 2018 no this is due to the resistance through a bad connection,as the demand becomes more for the spark it cant deliver the current/ signal to coil too spark in time causing misfire http://www.mkivsupra.net/vbb/showthread.php?61141-How-To-Refurbish-coil-pack-connectors Quote Link to comment Share on other sites More sharing options...
Milo500 Posted April 3, 2018 Author Share Posted April 3, 2018 no this is due to the resistance through a bad connection,as the demand becomes more for the spark it cant deliver the current/ signal to coil too spark in time causing misfire http://www.mkivsupra.net/vbb/showthread.php?61141-How-To-Refurbish-coil-pack-connectors If that was the case how would I know if one was not working correctly at high rpm...the demand is the same (spark wise) at 5kwhether it be at 0.7 bar or 1.5 bar No? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted April 4, 2018 Share Posted April 4, 2018 No, the required spark energy to jump a given spark gap increases exponentially with cylinder pressure, so the coil has to charge to a higher level to reliably spark as boost rises. As RPM is also rising it has to attain that energy level faster, too....The real answers are mappable dwell time and Bosch Motorsport coils, that pack enough Joules to drop a horse, but really healthy stock coils, with the connector shells and contact terminations in good order will suffice in many cases. Quote Link to comment Share on other sites More sharing options...
mellonman Posted April 4, 2018 Share Posted April 4, 2018 No, the required spark energy to jump a given spark gap increases exponentially with cylinder pressure, so the coil has to charge to a higher level to reliably spark as boost rises. As RPM is also rising it has to attain that energy level faster, too....The real answers are mappable dwell time and Bosch Motorsport coils, that pack enough Joules to drop a horse, but really healthy stock coils, with the connector shells and contact terminations in good order will suffice in many cases. Thanks Chris You don't have to change them but if you want your can to run correctly , you will have to change them like 90% of owners have had too over the years , put it this way I'm on my 5th turbo,3rd fuel pump, 3rd set of injectors , 3rd intercooler , 2 crank pulley , 2 set of coils , 2nd set of coil clips ,2nd cam sensor probably 4th battery 3rd set of wheels and 10th set of tyres. all things have a life and it looks like your coils or clips have passed theres Quote Link to comment Share on other sites More sharing options...
Milo500 Posted April 8, 2018 Author Share Posted April 8, 2018 Thanks Chris You don't have to change them but if you want your can to run correctly , you will have to change them like 90% of owners have had too over the years , put it this way I'm on my 5th turbo,3rd fuel pump, 3rd set of injectors , 3rd intercooler , 2 crank pulley , 2 set of coils , 2nd set of coil clips ,2nd cam sensor probably 4th battery 3rd set of wheels and 10th set of tyres. all things have a life and it looks like your coils or clips have passed theres So... I have changed the plugs to -8 ones and now it doesn't seem to cut. However it starts making a wastegate chatter noise above 5k ish and doesn't go any higher in the revs. Is odd, as it's on a screamer pipe you can clearly tell the gate is open. Quote Link to comment Share on other sites More sharing options...
Milo500 Posted April 10, 2018 Author Share Posted April 10, 2018 Right, so it still has the issue, it still cuts at 5k on 1.5 boost...I am now at a complete loss, please help haha...had allready booked the speed thing at japfest. Quote Link to comment Share on other sites More sharing options...
Ric Posted April 11, 2018 Share Posted April 11, 2018 Right, so it still has the issue, it still cuts at 5k on 1.5 boost...I am now at a complete loss, please help haha...had allready booked the speed thing at japfest. Did you change the coil pack clips? Quote Link to comment Share on other sites More sharing options...
mellonman Posted April 11, 2018 Share Posted April 11, 2018 have you changed the coils Quote Link to comment Share on other sites More sharing options...
Milo500 Posted April 12, 2018 Author Share Posted April 12, 2018 The coil packs are a possibility, however I am starting to think it is the speed sensor on the back of the gearbox Quote Link to comment Share on other sites More sharing options...
Ric Posted April 12, 2018 Share Posted April 12, 2018 Please follow peoples advice that you've asked for. at least 4 people have said change the coil pack clips and coils for a known good set. I can't see how a speed sensor would be related at all. Quote Link to comment Share on other sites More sharing options...
David P Posted April 12, 2018 Share Posted April 12, 2018 The coil packs are a possibility, however I am starting to think it is the speed sensor on the back of the gearbox Because this problem was apparently same with previous box it looks to be an old electrickery problem that your new box has inherited? But to confuse the issue even more, the Aristo box has 3.769:1 diff-ratio ratio gears in the no. 2 speed sensor which has also confused the gear-change tables? These gears can be swapped to increase or decrease the rpm of gear-changes. Info here. http://www.mkivsupra.net/vbb/group.php?discussionid=229&do=discuss And here. http://www.mkivsupra.net/vbb/group.php?discussionid=223&do=discuss Ellis ran a converted Aristo box in his Supra, maybe he has input re. resulting gear-change speeds? As I have already confirmed, the Aristo no. 2 speed sensor gears are definitely part of the problem, yet only by 100rpm. You also have another electronic issue that has lowered the engine rpm limit. Quote Link to comment Share on other sites More sharing options...
jagman Posted April 12, 2018 Share Posted April 12, 2018 "You also have another electronic issue that has lowered the engine rpm limit." As I have already pointed out there is a Rpm limiter that is to do with the park /neutral/ drive selection and I think it's around 5000 rpm - even if the box selects gears and the engine starts if the ecu thinks it's in park the limiter kicks in . The ECU has a few "limiters" each at a different rpm and each for a different reason and they do not always show up on self test of the ECU Quote Link to comment Share on other sites More sharing options...
Milo500 Posted April 12, 2018 Author Share Posted April 12, 2018 Please follow peoples advice that you've asked for. at least 4 people have said change the coil pack clips and coils for a known good set. I can't see how a speed sensor would be related at all. I have done everything people have suggested bar the coil packs...that is because I have not got round to getting a set to borrow yet. And yes as I have gone from a tt box to an aristo box, a speed sensor could be part of the problem? Quote Link to comment Share on other sites More sharing options...
Milo500 Posted April 12, 2018 Author Share Posted April 12, 2018 As I have already confirmed, the Aristo no. 2 speed sensor gears are definitely part of the problem, yet only by 100rpm. You also have another electronic issue that has lowered the engine rpm limit. Hi David. I have read that, and 're read it again to make sure I didn't miss anything. The aristo box I bought didn't come with one of the speed sensors (on the right hand side of the box when looking at the tail shaft end). So I had to take it out of the old tt box. As it is now doing the same thing it was doing before I changed the box, is what is making me think that it could be that speed sensor, as it is the only part I took from the old box Quote Link to comment Share on other sites More sharing options...
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