Guest johnny boy Posted December 11, 2009 Share Posted December 11, 2009 Hey guys I have a supra TT on a uk spec and auto box with some tuning running around the 500bhp mark at the moment. its done about 100k and has recently developed a problem when accelerating hard. Its almost like a rev limiter cuts in as you accelerate. If you use the car in manual or auto and give it the beens of the line it gets to approx 4k revs or under load and then almost cuts out powerlike bouncing against the rev limiter low down as the second turbo starts to kick in. I been told it may be the gearbox or the traction control but have had both reset and it has not worked. It also has an intermitant idle problem which a toyota specialist :rolleyes:thinks it could be the sensor and gear on the auto box thats worn and slips causing a cut in power to reduce damage. Is this right or could it be a number of things? its really annoying as i have all this power and cant use it as the car cuts out. Its the only problem i or my family have ever had with the car and in 7 years i cant say thats bad. i love the car and want to get it running smoothly again Any ideas of diagnosing would be great. please bare in mind that im not exactly technically minded so bare with me please. thanks in advance for any info you can give me. Quote Link to comment Share on other sites More sharing options...
bradleyh_15 Posted December 11, 2009 Share Posted December 11, 2009 does the power come back after its cut if you lift off and put the power back on? or is it just get to 4k then that's it no more what so ever? Quote Link to comment Share on other sites More sharing options...
edge Posted December 11, 2009 Share Posted December 11, 2009 Check spark plugs are right temp rating and not too old. Also check coil pack connectors Quote Link to comment Share on other sites More sharing options...
bignum Posted December 12, 2009 Share Posted December 12, 2009 (edited) Sounds like fuel cut, do you get the big red warning triangle as the power cuts, also it might help to provide some more info on the rest of the cars spec, i presume its a single turbo if you have 500 bhp. Edit, just read again its twin turbo so ignore the single, is the car decatted? Edited December 12, 2009 by bignum (see edit history) Quote Link to comment Share on other sites More sharing options...
Pig Posted December 12, 2009 Share Posted December 12, 2009 Sounds like you are BPU (Basic Performance Upgrade - have a search) and therefore not 500bhp. Never the less the UK spec at BPU is a truely awsome car. I had exactly the same problem on my UK spec a few years back and no one knew the answer then either. In short, the problem is a VSV valve i believe (cant remember the exact name for it) but whats happeneing is its sticking and not letting the 2nd turbo go on. Not an easy fix as to change it you have to take the turbo's off to replace the part. Good luck. Jon Quote Link to comment Share on other sites More sharing options...
BOB B Posted December 12, 2009 Share Posted December 12, 2009 It could be a fuel cut problem but as said we need more info on the spec of your car, also as Jon said it could be a vsv or it could be the ECGV actuator which is the problem with mine at the moment. Does the car allow you to go above 4,000 revs, but you have no power, or does it just stop you going above 4,000? Bob. Quote Link to comment Share on other sites More sharing options...
j1mb0b1 Posted December 12, 2009 Share Posted December 12, 2009 Sounds like you are BPU (Basic Performance Upgrade - have a search) and therefore not 500bhp. Never the less the UK spec at BPU is a truely awsome car. I had exactly the same problem on my UK spec a few years back and no one knew the answer then either. In short, the problem is a VSV valve i believe (cant remember the exact name for it) but whats happeneing is its sticking and not letting the 2nd turbo go on. Not an easy fix as to change it you have to take the turbo's off to replace the part. Good luck. Jon As said above on a twin turbos max you will get is around the 400bhp at the wheel. I had a problem like this and it turned out to be loose Coilpack connectors, Check that they have not come loose bud. Quote Link to comment Share on other sites More sharing options...
Guest johnny boy Posted December 13, 2009 Share Posted December 13, 2009 hey guys tbh the cars never been dyno'd so i was only quoting what ive been told. the car does rev above 4k and if i gradually apply the accelerator then it comes in fairly well. its when i give it the full power it gets between 4-5k and then cuts the power. no warning lights come on or anything. when i say it cuts out the engine doesnt stop it just stays at the power applied. for instance it stays at 80% power and then doesnt increase. i thought it was a air leak or coils plug but been told they are ok. sorry guys its hard to explain but if anyone lives close im happy to run themmout in the car! cheers john Quote Link to comment Share on other sites More sharing options...
Guest johnny boy Posted December 17, 2009 Share Posted December 17, 2009 right! been back to the mechanics today and have had the diagnostics on the car. A gearbox sensor has come up again and the guys have said that this is a fault and needs to be sorted anyway. I been told the gearbox sensor in question has a shaft with a plastic cog on it which monitor speed and this cog cold have worn and under heavy load slips causing the ecu to cut in and restrict the engine from causing too much damage. the guys have worked for toyotas for years and specialise in these now as a private garage but as they said they dont deal with tuned version much. what do you think guys does this soun d reasonable? Quote Link to comment Share on other sites More sharing options...
Terminator Posted December 17, 2009 Share Posted December 17, 2009 I have an Auto speed sender with nylon "cog" drive if you need it. You can do your own diagnostic check BTW. Quote Link to comment Share on other sites More sharing options...
d_d Posted December 19, 2009 Share Posted December 19, 2009 tuned version, its BPU Quote Link to comment Share on other sites More sharing options...
David P Posted December 20, 2009 Share Posted December 20, 2009 How long since you fitted a new fuel filter? Quote Link to comment Share on other sites More sharing options...
AndyT Posted December 20, 2009 Share Posted December 20, 2009 Search Error Codes John. It'll tell you how to check the cars diagnostics. Quote Link to comment Share on other sites More sharing options...
Guest johnny boy Posted December 20, 2009 Share Posted December 20, 2009 hey guys i havent changed the fuel filter for a while tbh. will get that done as well. terminator - how do i do my own diagnostic???? also how much would you want for the sensor and cog if its needed? also whats this about an upgraded BPU?????? Quote Link to comment Share on other sites More sharing options...
David P Posted December 20, 2009 Share Posted December 20, 2009 Hold your cursor over the letters BPU and all will be revealed Quote Link to comment Share on other sites More sharing options...
Pig Posted December 21, 2009 Share Posted December 21, 2009 As already said its the EGCV Actuator or the VSV valve. The bit that opens up for turbo 2 to work. At the min its getting stuck hence feeling like the car is restricted. I would reset your ECU and run your own diagnostic codes (there is a tutorial on this site) I also thought this was my gearbox when it first happened to me. Jon Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.