Joseph E Posted July 26, 2023 Report Share Posted July 26, 2023 i am pretty new to tuning learned how to do it on my car and have it tuned pretty well i am just concerned about my logging results as the engine rpm is shuttering on the log but the car doesnt seem to have any shutter in rpm in real time and runs pretty smooth was just hoping to get some insight the car is a 91 stealth tt at 15psi with a couple of mods plenty of fuel headroom afrs sit around 11:1 or lower the afrs on the logs are not accurate so dont worry about that appreciate any help thanks in advance the first log i took is 2nd and 3rd gear pull and the second log is a drive home so its a longer log upload for questions.llg drive home log.llg Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 26, 2023 Report Share Posted July 26, 2023 Can you attach a copy of the tune also. Can you do a triggerscope capture at idle and save that as a log then attach here. Quote Link to comment Share on other sites More sharing options...
Joseph E Posted July 26, 2023 Author Report Share Posted July 26, 2023 12 hours ago, Adamw said: Can you attach a copy of the tune also. Can you do a triggerscope capture at idle and save that as a log then attach here. yeah here is the tune and ill go grab that log in a sec traditional map.pclr 6 minutes ago, Joseph E said: yeah here is the tune and ill go grab that log in a sec traditional map.pclr 166.07 kB · 0 downloads and here is the trigger scope logs i took a handful of them just to be safe so what i was thinking it was is my plug wires or maybe coils or ptu something to do with the mechanical spark but wanted to ask on here before i go get parts because maybe i messed something up and its tune related but anyways i appreciate the response and look forward to hearing back from you Trigger Scope Log 2023-07-26 2;16;06 pm.llg Trigger Scope Log 2023-07-26 2;16;27 pm.llg Trigger Scope Log 2023-07-26 2;16;36 pm.llg Trigger Scope Log 2023-07-26 2;16;53 pm.llg Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 27, 2023 Report Share Posted July 27, 2023 The trigger looks ok to me so I suspect the "noisy" RPM in the log is real. I notice your lambda is all over the place, very rich in some areas, very lean in others, are you sure it is not misfiring? Quote Link to comment Share on other sites More sharing options...
Joseph E Posted July 28, 2023 Author Report Share Posted July 28, 2023 16 hours ago, Adamw said: The trigger looks ok to me so I suspect the "noisy" RPM in the log is real. I notice your lambda is all over the place, very rich in some areas, very lean in others, are you sure it is not misfiring? So it does a weird little missfire at idle sometimes not all times but every time I let off the throttle it leans all the way out and the actual lambda is not as rich as it says my calibration is off by about 2 points this slight missfire is what lead me to believe it was because of a mechanical issue such as injectors or ingnition wires I’ve had problems with it missfiring before on the stock ecu but when I put in the link it got a lot better and pretty much went away I will replace the plug wires and Hopfully get new injectors soon as well it very well could be misfiring due to lack of ignition power or bad injectors Quote Link to comment Share on other sites More sharing options...
DerekAE86 Posted July 28, 2023 Report Share Posted July 28, 2023 If you know the Lambda readings are wrong, why not just correct the calibration so they're correct? Quote Link to comment Share on other sites More sharing options...
Confused Posted July 28, 2023 Report Share Posted July 28, 2023 2 hours ago, DerekAE86 said: If you know the Lambda readings are wrong, why not just correct the calibration so they're correct? Maybe he's using an old AEM wideband, do no matter what he does, it'll always be out? But, seriously, you can't really expect for useful help and advice when you're telling us you're already ignoring a known basic configuration item...? Quote Link to comment Share on other sites More sharing options...
Joseph E Posted July 30, 2023 Author Report Share Posted July 30, 2023 On 7/28/2023 at 12:25 AM, Confused said: Maybe he's using an old AEM wideband, do no matter what he does, it'll always be out? But, seriously, you can't really expect for useful help and advice when you're telling us you're already ignoring a known basic configuration item...? Yes it’s an older aem I’ve tried to calibrate it but couldn’t get it right I went off of the gauge it’s off by 2 linearly so I just tuned based off that it’s not a perfect setup I’m trying to still get it dialed in completely Quote Link to comment Share on other sites More sharing options...
Confused Posted July 30, 2023 Report Share Posted July 30, 2023 You really should get the ECU knowing what the fuelling is doing, then you can use all the cool functions, set up closed loop lambda, fuelling based protection strategies, etc, but for that you'll need to pass on the AEM to someone who doesn't want to connect it to an ECU, and get yourself a better controller - the Link CANBUS one is utterly fantastic. Quote Link to comment Share on other sites More sharing options...
Joseph E Posted July 31, 2023 Author Report Share Posted July 31, 2023 20 hours ago, Confused said: You really should get the ECU knowing what the fuelling is doing, then you can use all the cool functions, set up closed loop lambda, fuelling based protection strategies, etc, but for that you'll need to pass on the AEM to someone who doesn't want to connect it to an ECU, and get yourself a better controller - the Link CANBUS one is utterly fantastic. Good to know I will look into the link cambus lambda I’ve heard about it and will most likely go with that one and I’m not entirely sure what the closed loop lambda does I’ve just really dipped my toes into the water I got my car running pretty good but still not very adept with the program I have a lot more to learn Quote Link to comment Share on other sites More sharing options...
DerekAE86 Posted July 31, 2023 Report Share Posted July 31, 2023 Closed Loop means the ECU is getting feedback on the changes its making. So in the case of Lambda; if it commands a certain amount of fuel to be injected and the feedback from the Lambda sensor indicates it wasn't enough(or too much) fuel to meet the Lambda target it can continue to add(or remove) fuel beyond what's been set in your Fuel Table. Without a Lambda sensor connected the ECU just has to assume it has commanded enough fuel to meet the target. Quote Link to comment Share on other sites More sharing options...
Joseph E Posted August 1, 2023 Author Report Share Posted August 1, 2023 21 hours ago, DerekAE86 said: Closed Loop means the ECU is getting feedback on the changes its making. So in the case of Lambda; if it commands a certain amount of fuel to be injected and the feedback from the Lambda sensor indicates it wasn't enough(or too much) fuel to meet the Lambda target it can continue to add(or remove) fuel beyond what's been set in your Fuel Table. Without a Lambda sensor connected the ECU just has to assume it has commanded enough fuel to meet the target. Alright and that applies to anything that can run on a closed loop. so it’s basically a fuel trim table? My stock ecu had fuel and knock trim issues which was part of the reason I upgraded. I’m definitely gonna get a new wideband and set it up as a closed loop system seems exactly what I’m looking for Quote Link to comment Share on other sites More sharing options...
DerekAE86 Posted August 1, 2023 Report Share Posted August 1, 2023 1 hour ago, Joseph E said: Alright and that applies to anything that can run on a closed loop. so it’s basically a fuel trim table? Yes and no. Closed loop doesn't just mean fuel. For example you can run closed loop idle control. Where the ECU will open the idle valve to increase idle, recieve feedback on how the rpm has changed, then readjust the idle valve up or down to meet the target. Same for closed loop boost control, open the wastegate to bleed off boost pressure, recieve feedback on what the manifold pressure is, then open or close the wastegate more to maintain the required boost target. With closed loop lambda control. It's not a "trim table" that is setup before hand, but it will "trim" the fuel within the constraints you set to allow it to meet the fuel ratio target. So you can set it to allow a maximum of 30% extra fuel if required. But this doesnt mean it will always add 30%, it will only add what it needs to maintain the target. Then you can set it to only allow a minimum of say -10% less fuel. So you can prevent it accidently going too lean. However closed loop lambda should never be used as a replacement for a good tune. It's really only to make small adjustments due to changes in atmospheric conditions (temp/pressure/etc) or maybe changing fuel quality. Quote Link to comment Share on other sites More sharing options...
Joseph E Posted August 1, 2023 Author Report Share Posted August 1, 2023 15 hours ago, DerekAE86 said: Yes and no. Closed loop doesn't just mean fuel. For example you can run closed loop idle control. Where the ECU will open the idle valve to increase idle, recieve feedback on how the rpm has changed, then readjust the idle valve up or down to meet the target. Same for closed loop boost control, open the wastegate to bleed off boost pressure, recieve feedback on what the manifold pressure is, then open or close the wastegate more to maintain the required boost target. With closed loop lambda control. It's not a "trim table" that is setup before hand, but it will "trim" the fuel within the constraints you set to allow it to meet the fuel ratio target. So you can set it to allow a maximum of 30% extra fuel if required. But this doesnt mean it will always add 30%, it will only add what it needs to maintain the target. Then you can set it to only allow a minimum of say -10% less fuel. So you can prevent it accidently going too lean. However closed loop lambda should never be used as a replacement for a good tune. It's really only to make small adjustments due to changes in atmospheric conditions (temp/pressure/etc) or maybe changing fuel quality. Cool so it’s a safety measure I’ve seen the open and closed loop terms thrown around in the software so I’m glad I know what they mean now I appreciate the help and knowledge I’m glad I posted on the forums I’ve been met with some bad responses on the 3000gt forums before when I was a lot younger because I was pretty ambitious so I appreciate the kindness Quote Link to comment Share on other sites More sharing options...
DerekAE86 Posted August 2, 2023 Report Share Posted August 2, 2023 18 minutes ago, Joseph E said: so it’s a safety measure I’ve seen the open and closed loop terms thrown around It's only a safety measure if it's been setup correctly. An incorrect CL setup can actually make things worse. Open Loop only means there is no feedback from the resulting output back to the input. The feedback "Loop" is "Open". Like in electronics when you have an "Open" switch, it means there is no connection. Quote Link to comment Share on other sites More sharing options...
Vaughan Posted August 2, 2023 Report Share Posted August 2, 2023 When talking specifically about Lambda the Open loop means that it applies corrections based on the lambda/afr target table values because you can also turn off open loop Lambda in which case changing Lambda/AFR target values would have no effect on the amount of fuel being injected Quote Link to comment Share on other sites More sharing options...
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