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'93 / '95 Del Sol Si - '95 DX Coupe - '00 Accord EX F23 Manual
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Discussion Starter #1 (Edited)
Ok, so webdesaster 's question about closed loop got me going. I started doing some reading and then I decided to mess with closed loop a little bit myself. However, I'm not running narrow band like he is.

I have never ran "closed loop" on a tuned motor. Ever. I've always just marathon tuned, nailed down all my AFRs and ran in open loop. I decided to experiment and went to my Emission Control Parameters to see what I could mess up. I chose AEM / UEGO / stock settings and "Fixed - Target Stoich" below.

Running a closed loop wideband is appealing to me these days. So.....
For you guys that use this on a regular basis -

**What do you guys generally do about using o2 Sensor Heater Feedback?
Do you use it?

**What about "Targeting Mode"? What are your positive / negative experiences with *Fixed (Target Stoich) and Variable (Target Lambda Tables)?

**Since the wideband is already feeding information into D14, How do you guys usually set up your widebands when switching over to "closed loop"? Any changes?


***If using wideband for closed loop, what settings have worked for you as far as lowering the fuel adjustment settings. I've read over and over about lowering these percentages due to the resolution of the wideband.

I'd like to learn / understand this function 100% since I've never used it before.


EDIT - If you have set up a wideband to replace your narrow band OUTSIDE of a Crome Gold ROM, I'd like to hear from you too and how you set it all up.
 

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93 Civic HB SI
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770 Posts
1. I didn't realize heater circuit had feedback on these ECUs? If so, it might state a parameter like heater status, but it can't be used in conjunction with an input I don't believe. In most cases, heater control circuit is simply the ECU monitoring and controlling heater amperage on the circuit with a PWM driver and current sensing device inside the ECU. It will quickly switch ground to the heater since heater always receives power KOEO, to warm the element slowly and maintain amperage on startup below a threshold (this varies per sensor and OEM). Once it gets warm, amperage rate begins to fall and the ECU will maintain a constant amperage rate via PWM (determined through R&D) to keep heater Temps at a set temp for optimal performance. On these ECUs I dont think the heater circuit can be used for heater feedback, since it is only an output and circuit amperage performance is internally monitored within the ECU. Maybe your saying your wideband controller has a heater feedback parameter or something? I'm curious what you mean :)

2. Fixed target is exactly what it says, set it and forget it lol. ECU will interpret feedback from your wideband controller and attempt to modify fuel trims to bring AFR strictly to a single value. Variable is probably the best to use since you can configure a range/window of operation that you allow the ECU to maintain, its less stringent and can allow for smoother operation during stop and go. Closed loop should really only be allowed to alter fuel trims while out of high load situations. Almost all OEMs switch to open loop when you romp down on the throttle and enter high load ranges. Therefore, your closed loop settings should have thresholds configured to determine when open vs closed loop is active. You can disable/enable closed loop via combo MAP, RPM, TPS and temp sensor values. Also, the engine should be allowed to warm to a decent ECT before enabling closed loop, since targeting an AFR static or variable range somewhere around 13-15 on cold startup idle might kill the engine, needs to be a bit rich until temps come up.

3. As long as you've configured the lambda/AFR to controller voltage output relationship correctly in your crome settings, explicitly stating the ranges (like 0V = 0.68 [10:1 pump gas] and 5V = 1.36 [20:1 pump gas] or whatever they are for your specific controller found in your controller manual), then you can simply set your targets directly with lambda/AFR values using the closed loop target/tuning tools available to you through your software, since interpolation to voltage should be handled by the application running the closed loop function.


All I know, myself nor my tuner could get my stupid car to idle properly on E85 with my FIC1000's in open loop when warm, probably a behavior trait with the larger injectors running tiny amounts of on time at idle. Allowing the ECU to run in closed loop at idle fixed it, smooth as butter, 13-14:1 at idle. 14-15:1 part throttle cruise on the street/highway is nice :), then my 11-12:1's in open loop show their ugly faces when I hit the gas lol
 

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'93 / '95 Del Sol Si - '95 DX Coupe - '00 Accord EX F23 Manual
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Discussion Starter #3 (Edited)
I have used Crome for years. But always used p30 maps. Lately, I've been using Crome Gold. In the options menu (Emissions Control), you have the ability to switch your o2 sensor to wideband and also have the ability to check the box for "o2 Sensor Heater Feedback". I was wondering if anyone used this and why. I've included a pic of the box I'm referring to as well as the "Emissions Control" area in general.

I totally understand the Fixed Target and Variable settings..but was wondering if people have had better luck using the wideband o2 to monitor and change (like a narrowband) their cars using one or the other. As we all know, Crome (and all tuning apps) can be tempermental with certain cars or whatever.

Since I've really never used Crome Gold other than just looking it over, these options / settings are pretty new to me. With the p30 options, I can get in and get out like a Ninja.

Thanks for the response, man. Here are the Gold "Emissions Control" settings with the o2 Sensor Heater Feedback option.

This setting alone is one of the things that makes a Gold ROM so much different than using a P30.

136535
 

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'93 / '95 Del Sol Si - '95 DX Coupe - '00 Accord EX F23 Manual
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Discussion Starter #4
Also -
I was doing some searching and stumbled on this. In this guy's Crome Gold settings, he is using the "o2 Sensor Heater Feedback" option. However, the post is so damn old that it's probably useless to ask the dude about his settings.

136536
 
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