Tricky-Ricky Posted July 30, 2006 Share Posted July 30, 2006 I think i have read that the TT ECU comes out of closed loop at 4,000 RPM ? but there also must be a boost setting at which it comes out of closed loop regardless of RPM, anyone know? Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted July 30, 2006 Author Share Posted July 30, 2006 Did a search, but couldn't turn up anything, has nobody managed to read the std maps? Quote Link to comment Share on other sites More sharing options...
Matt Harwood Posted July 30, 2006 Share Posted July 30, 2006 but there also must be a boost setting at which it comes out of closed loop regardless of RPM, anyone know? I don't think so. I can get 1 bar of boost just before 4krpm, and the ECU still insists on being in closed loop. Although, I'm running an E-manage signal fudger so the ECU is probably only seeing about 0.6 bar, but it's still closed loop. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted July 31, 2006 Author Share Posted July 31, 2006 Hmm, seems a bit daft to me that Toyota would go to the trouble of having a boost cut in case the injectors can't keep up, but not have some kind of open loop enrichening, should say a VSV fail and the system go into TTC mode;) if the factory fuel mapping is happy seeing 0.7-0.8 bar before 4,000 rpm then the timing must be quite conservative below 4.000 rpm. Quote Link to comment Share on other sites More sharing options...
bondango Posted July 31, 2006 Share Posted July 31, 2006 Does the TCCS not determine closed loop operation based on the values of RPM, AFM, AIT and Boost reference..as well as TPS Quote Link to comment Share on other sites More sharing options...
Matt Harwood Posted July 31, 2006 Share Posted July 31, 2006 AFAIK, closed loop kicks in at 4krpm, (I think it's actually 3800), or full throttle, and thats it... I stand to be corrected though Quote Link to comment Share on other sites More sharing options...
bondango Posted July 31, 2006 Share Posted July 31, 2006 AFAIK, closed loop kicks in at 4krpm, (I think it's actually 3800), or full throttle, and thats it... I stand to be corrected though Closed looop is when the TCCS controls fueling etc by using the oxy sensors etc and trys to maintain a steady AF of around 14. when you go WOT which can be anything above 4Krpm, or other conditions such as boost level, TPS position etc etc you go into open loop - where fueling is adjusted via ecu maps and fuel pressure etc etc ..."In closed loop operation the ECU uses one or more oxygen sensors as a feedback loop in order to adjust the fuel mixture. This gives the name ‘closed loop’ from the closed feedback loop. The ECU won’t run in a closed feedback loop all the time, so ‘open loop’ is used to describe the operation of the ECU when the mixture is not being adjusted in this way (usually when the engine is cold or when running under high load). In closed loop operation the ECU uses the oxygen sensor to tell if the fuel mixture is rich or lean. However, due to the characteristics of the oxygen sensor it can’t tell exactly how rich or lean, it only knows that the mixture is richer or leaner than optimum. The ECU will enrich the mixture if the oxygen sensor shows that the mixture is lean, and lean the mixture if it looks rich. The result of this is that the mixture will swing back and forward around the stoichiometric point...." Quote Link to comment Share on other sites More sharing options...
Matt Harwood Posted July 31, 2006 Share Posted July 31, 2006 oops, yeah I know that, I meant open loop/hard written map Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted July 31, 2006 Author Share Posted July 31, 2006 So has anyone got ROM maps from the ECU? as i said i would be interested to see just what else will force the ECU to go open loop besides just RPM, most other ECUs use air temp or water temp and also TPS and boost, have any of the US guys managed to pull the std fuelling and timing maps from a J spec TT. Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 31, 2006 Share Posted July 31, 2006 I've found these: 4000rpm+ A large throttle delta Wide open throttle Lifting off the throttle completely Below a certain coolant temp (I don't know what though as the EMU calibration is off, unless my car really runs at 55degC ) Amazingly I don't think boost pressure comes into it. -Ian Quote Link to comment Share on other sites More sharing options...
bondango Posted July 31, 2006 Share Posted July 31, 2006 Below a certain coolant temp (I don't know what though as the EMU calibration is off, unless my car really runs at 55degC -Ian think thats under cold start conditions Ian, i.e. until engine has reached normal operating temps. Strange though how boost dosnt seem to play a part, i think there were maps at one point on SONIC or SOGI that had been extracted on the techtom heres the stock ignition map http://suprasonic.org/sonictech/techtom/RCTS_2JZ_IGNITION.jpg Thought the fuel map for was around too.. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted July 31, 2006 Author Share Posted July 31, 2006 Ian have you used the EMU feature to force open loop? or do you feel its unnecessary? i am actually going to be removing some fuel in open loop but will need to add some in closed loop as the boost rises, hence trying to get as much info on what forces open loop normally, i would still very much like to see the std maps thought, suppose i should save myself the hassle and just get PFC or similar, but don't want to end up spending loads at the moment;) Quote Link to comment Share on other sites More sharing options...
JohnA Posted July 31, 2006 Share Posted July 31, 2006 .... i am actually going to be removing some fuel in open loop but will need to add some in closed loop as the boost rises,.. You can't add fuel in closed-loop, that's the whole idea:d If you do try, the ECU will trim back the injector duty to bring it back to stoich. Even worse, it may decide to affect some of the open-loop maps as well, making them leaner. You don't want that. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted July 31, 2006 Author Share Posted July 31, 2006 You can't add fuel in closed-loop, that's the whole idea:d If you do try, the ECU will trim back the injector duty to bring it back to stoich. Even worse, it may decide to affect some of the open-loop maps as well, making them leaner. You don't want that. You misunderstand John, there is a feature on the EMU that will allow you to fudge the signal and force the ECU into open loop earlier, especially so you can add fuel, that was my point in trying to find exactly what had what effect on std ECU operation, if i know the exact parameters it will make things a bit essayer. Quote Link to comment Share on other sites More sharing options...
Fly Posted March 3, 2014 Share Posted March 3, 2014 sorry, to drag up a eight year old thread but i have been seaching and this seems to be the only one close! Firslty if you can get the ECU to go into open loop by fudging a signal somewhere is there any long term health issues that you would expect? From what i have read the ECu drives to a 12 ish to 1 afr in open loop but 14/1 in closed so you might reduce your MPG but mean that the stock ecu doesnt fight the piggyback in the area that would be closed loop normally. Secondly could a narrowband simulator be used and set to a constant voltage to force the stock ECU into open loop? Quote Link to comment Share on other sites More sharing options...
Fly Posted March 3, 2014 Share Posted March 3, 2014 or setting a constant voltage / afr from the simulated narrowband to prevent the stock ecu from seeing fluctuating afrs and stop trimming the fueling? Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted March 3, 2014 Author Share Posted March 3, 2014 LOL! that was a while ago, I found the only way to adjust fueling while in closed loop was to tweak the std lambda signal. IE if you want to richen or weaken the fueling during closed loop you make the adjustment but make the std lambda signal to the ECU see the expected signal, there are devices to do this, and from memory there was a Greddy one. Obviously this only applies to piggybacks, as on a standalone you can set the parameters for closed loop or not. PS I think you will find that setting a constant voltage to the ECU from a lambda sensor will cause the ECU to think its faulty as the expected signal is constantly variable. Quote Link to comment Share on other sites More sharing options...
Whitesupra95 Posted March 3, 2014 Share Posted March 3, 2014 I couldn't see anywhere on this thread with wideband results showing that it's still at stoich below 4k. Like people have said earlier, it's a pretty stupid setup from the factory considering the first turbo is in around 2000rpm. I'll maybe chuck my wideband on out of curiosity lol Saying that not sure my lambdas working after it cost me £30 to do 60miles ha ha Quote Link to comment Share on other sites More sharing options...
Fly Posted March 3, 2014 Share Posted March 3, 2014 yea sorry Ricky to drag it up, having dug a little more i dont think my idea of the same voltage would work either as the stock ecu would try and trim that back to stoich or keep the ecu in closed loop longer. I did have another thought of using an aux output from emanage to the TPS wire on the stock ecu setting it to WOT all the time but then i dont know what other issues this would cause. As for changing the stock lambda value, surely changing my output voltages on my narrowband simulator would do the same? Anyway having had a chat with Noz and a rethink i am not sure the closed loop operation will cause me issues as i will be significantly leaner than stock until i hit boost so both the emanage and stock ecu will want to add fuel rather than trim it off in closed loop. Still i think being able to force the ECU into open loop is a much easier solution with a piggy. Thanks for your input here fellas i am just trying to soak up as much info as possible. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted March 3, 2014 Author Share Posted March 3, 2014 Like I said stable voltage from std lambda results in ECU thinking the lambda has failed so it will result in richer fueling. Yes you can use the wide-band simulated NB output to scue the lambda feedback to the ECU to allow you to change the fueling while the std ECU thinks its normal/stoic, that how I did it. Regarding using the TPS, I haven't tried that but I think you will find there are more than one trigger for open loop. As for your last comment, as long as the std ECU thinks its seeing a normal lambda feedback, you can have whatever fueling you like, you tell the EMU how you want the fueling, there is not lambda feedback for it, unless you enable the self map feature, which I wouldn't advise anyway. Quote Link to comment Share on other sites More sharing options...
mellonman Posted March 3, 2014 Share Posted March 3, 2014 I couldn't see anywhere on this thread with wideband results showing that it's still at stoich below 4k. Like people have said earlier, it's a pretty stupid setup from the factory considering the first turbo is in around 2000rpm. I'll maybe chuck my wideband on out of curiosity lol Saying that not sure my lambdas working after it cost me £30 to do 60miles ha ha Trust me it is ! the stock ecu will stay at stoich up until 0.5 bar or 4000rpm is met I have a wide band and a stock ecu Quote Link to comment Share on other sites More sharing options...
Whitesupra95 Posted March 3, 2014 Share Posted March 3, 2014 That's crazy lol Quote Link to comment Share on other sites More sharing options...
Fly Posted March 3, 2014 Share Posted March 3, 2014 Even on the na? Quote Link to comment Share on other sites More sharing options...
mellonman Posted March 3, 2014 Share Posted March 3, 2014 Not sure about the N/A i belive its even later and even when it goes into open loop its only down to 13 afr i read somewhere Just to clean this up the ecu will only stay at stoich at 0.5 bar if it has been achived from a slow build up of light throttle , it will swing into open loop on many factors - throttle position, speed , load , rpm even the water temp sensor has some input ie cold start so must be monitored all the time Quote Link to comment Share on other sites More sharing options...
Fly Posted March 3, 2014 Share Posted March 3, 2014 Thanks mello, this has given me something to think about. Quote Link to comment Share on other sites More sharing options...
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