namre Posted January 5, 2019 Report Share Posted January 5, 2019 Hello, We have engine hesitation esp. at boost area after retuning. We checked the mechanical possibilities but could not find anything. The tuner says runtime values are ok at that stage. Here is the base map. Do you have any clue if there is any signal that this is about tuning? Thanks for your help. Quote Link to comment Share on other sites More sharing options...
Richard Hill Posted January 5, 2019 Report Share Posted January 5, 2019 Can you post a log file too? That would definitely help to see what might be causing the problem. Quote Link to comment Share on other sites More sharing options...
Rob W Posted January 5, 2019 Report Share Posted January 5, 2019 What engine is this? Quote Link to comment Share on other sites More sharing options...
namre Posted January 6, 2019 Author Report Share Posted January 6, 2019 It's subaru sti 2.5. I will record the log file asap. Quote Link to comment Share on other sites More sharing options...
namre Posted January 6, 2019 Author Report Share Posted January 6, 2019 16 hours ago, Richard Hill said: Can you post a log file too? That would definitely help to see what might be causing the problem. Hello, Here are some log files I got. Hope it helps. high boost2.llg high boost3.llg highboost.llg lowboost.llg Quote Link to comment Share on other sites More sharing options...
Tim D Posted January 6, 2019 Report Share Posted January 6, 2019 I see a couple of things from the log that might be worth a look (pic attached) 1. It looks quite rich (0.68) at the start of boost, before stabilising later. 2. Boost Mode is set to 'closed loop' but the Target Boost Table only has a row for TP = 0%. It should include rows up to TP = 100%. Boost Status is shown as OFF all the time, due to the above I expect. Hope that helps? Quote Link to comment Share on other sites More sharing options...
namre Posted January 6, 2019 Author Report Share Posted January 6, 2019 2 hours ago, TimmyD said: I see a couple of things from the log that might be worth a look (pic attached) 1. It looks quite rich (0.68) at the start of boost, before stabilising later. 2. Boost Mode is set to 'closed loop' but the Target Boost Table only has a row for TP = 0%. It should include rows up to TP = 100%. Boost Status is shown as OFF all the time, due to the above I expect. Hope that helps? Thanks for the reply. I am confused at boost target table in the way that if conflicts with EVC. would it stabilize the boost further than wastegate? finally I appreciate if you share a sample target table since I couldnot find it in the base maps? Quote Link to comment Share on other sites More sharing options...
Tim D Posted January 6, 2019 Report Share Posted January 6, 2019 I'm not sure what you mean by "EVC" ? I believe that you're basically running open loop, i.e. from the wastegate table. However, the Boost Mode is set to 'closed loop'. I don't think this is what's causing your "engine hesitation" problem, but it would be a good refinement to carry out at some point. From Impreza STI, 2.5 (2007), here's Target boost table: I think the first thing to tackle is the fuelling IMHO.... Quote Link to comment Share on other sites More sharing options...
namre Posted January 7, 2019 Author Report Share Posted January 7, 2019 5 hours ago, TimmyD said: I'm not sure what you mean by "EVC" ? I believe that you're basically running open loop, i.e. from the wastegate table. However, the Boost Mode is set to 'closed loop'. I don't think this is what's causing your "engine hesitation" problem, but it would be a good refinement to carry out at some point. From Impreza STI, 2.5 (2007), here's Target boost table: I think the first thing to tackle is the fuelling IMHO.... Many thanks. I will check the fueling first. By EVC I meant that I have electronic valve controller (HKS) installed. So I have several boost modes. I am not sure according to which mode should I fill this table. Will it deteriorate the other modes for example? That's what I'm confused. Is it better to change it basically to open loop if that's already the case in practice? Quote Link to comment Share on other sites More sharing options...
namre Posted January 7, 2019 Author Report Share Posted January 7, 2019 Do you have any hint on whats happening in lower rpms? It happens when trying to stabilize the rpm but not on acceleration. Could it be also fuel related? This time AFR seems to be within the limits. lowboost.llg Quote Link to comment Share on other sites More sharing options...
Tim D Posted January 7, 2019 Report Share Posted January 7, 2019 An "electronic valve controller", sorry I never realised that. In that case, I guess you wouldn't want the Link ECU doing closed loop aswell. My mistake. Looking at your latest log, despite the oscillations they look pretty small in amplitude (it's zoomed in quite a lot). Bit stuck on this I'm afraid, apart from the fuelling on acceleration looking too rich. I could have helped with setting up Link boost control, but I don't think that's your problem now. Quote Link to comment Share on other sites More sharing options...
namre Posted January 8, 2019 Author Report Share Posted January 8, 2019 13 hours ago, TimmyD said: An "electronic valve controller", sorry I never realised that. In that case, I guess you wouldn't want the Link ECU doing closed loop aswell. My mistake. Looking at your latest log, despite the oscillations they look pretty small in amplitude (it's zoomed in quite a lot). Bit stuck on this I'm afraid, apart from the fuelling on acceleration looking too rich. I could have helped with setting up Link boost control, but I don't think that's your problem now. I'm really confused. Ok my fuel pressure was a bit lower. I have corrected that one and problem at acceleration was decreased. I realized that hesitation at the low TP was not happening when the engine is cold/warm (say before flooring). But it starts appearing after flooring couple of times. So there is no hesitation at 100% TP, but there is hesitation after travelling (not before). If it was ignition it should appear at flooring as well in my opinion. We have checked the plugs/gap they were ok. Only remaining candidate might be fuel pump but then why its not happening at all circumstances then? That's why I tried to check tuning as well since this wasnt the picture before retuning. Totally stucked here. Quote Link to comment Share on other sites More sharing options...
Tim D Posted January 8, 2019 Report Share Posted January 8, 2019 One thought, are you able to reload the old 'tune' to prove the problem can be reversed? Quote Link to comment Share on other sites More sharing options...
namre Posted January 10, 2019 Author Report Share Posted January 10, 2019 I will try it as soon as I have time. But as far as I recall there was no bucking at least was not noticeable this much. I tried to eliminate mechanics -changed the fuel pump and plugs but no luck. Would TPS calibration help? Quote Link to comment Share on other sites More sharing options...
namre Posted January 11, 2019 Author Report Share Posted January 11, 2019 Is it a bad idea to adjust fuel or ignition table according to this specific spot in order to eliminate problem from most probably my cams (being stage 3)? i know this will hurt my afr. general question is that should the fuel and ignition tables have sequentially increasing or decreasing values all of the time? is it possible to have some unsequential jumps where for example afr is off target? thanks. Quote Link to comment Share on other sites More sharing options...
Rob W Posted January 11, 2019 Report Share Posted January 11, 2019 Does the bucking sound like a lean misfire? Popping? Your target Lambda at 65kpa is .95. It is oscilating between 1.04 and .98 over about 5kpa range in a very steady throttle position (out of your low boost log.) Quote Link to comment Share on other sites More sharing options...
namre Posted January 18, 2019 Author Report Share Posted January 18, 2019 update: my lambda values on the ecu was crap since calibration was wrong. could not find the correct values but we have retuned fuel according to gauge this time. most of the bucking went away and it's better now. so there were wrong afr values in ecu readings. now only in 2nd gear if you force to drive constantly at 2500 rpm there is a little bucking and i guess this is normal? Rob W 1 Quote Link to comment Share on other sites More sharing options...
Rob W Posted January 18, 2019 Report Share Posted January 18, 2019 So it was lean? Good to hear you have it sorted Quote Link to comment Share on other sites More sharing options...
Ken Dunkley Posted January 18, 2019 Report Share Posted January 18, 2019 Hi- An old saying is - An engine wants what it wants - . Perhaps make it richer in the areas where you feel this noticeable bucking. To me this is a sign of running lean . With your cams you can get intake reversion and all sorts of weird pressure waves happening that can effect smooth running . Especially at that point of light throttle and low/medium engine speed . Dont be stuck on A/F targets at this particular problem area - Try it at 0.9 and see how it runs . Rob W 1 Quote Link to comment Share on other sites More sharing options...
Rob W Posted January 18, 2019 Report Share Posted January 18, 2019 5 minutes ago, Ken Dunkley said: Hi- An old saying is - An engine wants what it wants - . Perhaps make it richer in the areas where you feel this noticeable bucking. To me this is a sign of running lean . With your cams you can get intake reversion and all sorts of weird pressure waves happening that can effect smooth running . Especially at that point of light throttle and low/medium engine speed . Dont be stuck on A/F targets at this particular problem area - Try it at 0.9 and see how it runs . Well said Ken. I mentioned in another forum that the wideband only measures "burnt fuel" and the cams skew the readings. Mine Ej engine runs best at cruise .9-.95 with cams rather than the more traditional 1.0+ Ken Dunkley 1 Quote Link to comment Share on other sites More sharing options...
namre Posted January 19, 2019 Author Report Share Posted January 19, 2019 yeah they were all lean due to wrong calibrated afr. now i will check the latest small era at 2nd gear from your point of view thanks. Quote Link to comment Share on other sites More sharing options...
namre Posted January 19, 2019 Author Report Share Posted January 19, 2019 jackpot. it's also gone. i put the spot somewhat richer than it was. thanks Quote Link to comment Share on other sites More sharing options...
namre Posted January 23, 2019 Author Report Share Posted January 23, 2019 still related to this: after solving the problems of bucking and idle, i accidentally realized that sometimes there is a strong bucking at very slow speed between 1000-1500 rpm. i tried to search for the cause and i have found that it happens when idle ignition control kicks in and locks out momentarily. meaning that you are driving slow and releasing the gas pedal a little bit and just after that put back again. attached are my screenshots and also log file. you can see that when it happens ap drops to 0 at a very short time and then idling starts to lower rpm by retarding the ignition. but then when you put back your foot again, ignition table starts to work and confusion occurs. i think only workaround would be putting a zero to speed lockout but then there is no point of having an idle system since it will be high or floating again at slow speeds. and the questions: is it so that my ignition table and idle ignition table contradicts a lot? might this be the reason? if so would it mean that i should have -15 degrees in ignition table somewhere synced to idle ignition table? and if so is it possible to have this kind of numbers as they will be far far away from the base map. thanks in advance for your support. Log 2019-01-23 7;06;48 pm.llg Quote Link to comment Share on other sites More sharing options...
ClintBHP Posted January 23, 2019 Report Share Posted January 23, 2019 The idle ignition table should be a lot smoother than that, they 4 degrees a cell up and down from 0 idle error, also lock out the idle strategy while the vehicle is moving. Quote Link to comment Share on other sites More sharing options...
cj Posted January 23, 2019 Report Share Posted January 23, 2019 I think you've misunderstood what the idle control table does. Its not "additive" to your ign1 table, it *replaces* your ign1 table when its active. The axis at the top is how far above or below target idle you are. What this means is you go from 25 ish * ign when outside the idle control parameters, and as soon as idle control kicks in, it drops to 15*. This is already quite a bit of a jump, and I try to get the ign1 value to be the same as the 0 ignition idle table number so that there is no "jump" when you go into idle control. Think about this though, if your idle control parameters specify a target of 1000 rpm, but your idle control is allowed to kick in at 1200rpm due to its control parameters, your car goes from 25-30*, straight to -6* ign. This is going to be a huge loss of power, and i'm not surprised its noticeable. Here is an example ign1 table on this car has 18* at the idle region so there is next to no change as it goes from "normal" to "idle". Quote Link to comment Share on other sites More sharing options...
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