Rev built MS3 Basic idle readjustments
#1
Rev built MS3 Basic idle readjustments
Gents,
With a lot of help, the car seems to be fixed. https://www.miataturbo.net/engine-pe...p-91105/page6/ Thanks. I sent Nigel some beer money.
Now I need to tackle some things I haven't wanted to mess with. Since installing the lower mileage JDM bottom end and updating the base timing, an idle droop I had conquered is back. I know I need to go through the whole idle adjustment procedure but wanted to post my tune and ask if there's anything really heinous I need to change before running the idle adjustment procedures. I had planned to mess with her today, but we've got a steady, cold rain. We're having company for Christmas. No way I'll be released to the garage before Tuesday.
My plan is to follow the advise here https://www.miataturbo.net/megasquir...ed-help-90819/
and instructions here Mega Miata: Closed Loop Idle REV 2.2 (Will these work on MS3 Basic running firmware 1.2.0?)
I have three issues. First, if I rev the engine or move the car before the O2 sensor is providing an actual reading, the idle gets all wonky. I have to shut her down, restart and wait. I've learned to live with it, but sometimes, like making room for the next guy to get gas at the track, I'll move the car out of the way, shut her down...etc. Now that I know a little more about EGO Correction, it seems logical something would happen, but is there anything I can do? She has always done that since installing the MegaSquirt.
I'm seeing cold start, cold temp idle AFRs in the low 11s. When she warms up, I'm getting around 14.7. I think part of the reason is she's getting cold air from the left front wheel well rather than under hood air, coupled with the huge TSE radiator and 180 degree thermostat. Are my Warmup Enrichment and ASE settings okay?
If I start her when reasonably warm, say sitting in the sun in the parking lot on a cool day when I come out to go get lunch, even if I sit with her idling for a few minutes till the idle drops, the next time I push in the clutch the idle will shoot up to about 2000 for just a second or two, then ramp down.
Thanks and Merry Christmas,
With a lot of help, the car seems to be fixed. https://www.miataturbo.net/engine-pe...p-91105/page6/ Thanks. I sent Nigel some beer money.
Now I need to tackle some things I haven't wanted to mess with. Since installing the lower mileage JDM bottom end and updating the base timing, an idle droop I had conquered is back. I know I need to go through the whole idle adjustment procedure but wanted to post my tune and ask if there's anything really heinous I need to change before running the idle adjustment procedures. I had planned to mess with her today, but we've got a steady, cold rain. We're having company for Christmas. No way I'll be released to the garage before Tuesday.
My plan is to follow the advise here https://www.miataturbo.net/megasquir...ed-help-90819/
and instructions here Mega Miata: Closed Loop Idle REV 2.2 (Will these work on MS3 Basic running firmware 1.2.0?)
I have three issues. First, if I rev the engine or move the car before the O2 sensor is providing an actual reading, the idle gets all wonky. I have to shut her down, restart and wait. I've learned to live with it, but sometimes, like making room for the next guy to get gas at the track, I'll move the car out of the way, shut her down...etc. Now that I know a little more about EGO Correction, it seems logical something would happen, but is there anything I can do? She has always done that since installing the MegaSquirt.
I'm seeing cold start, cold temp idle AFRs in the low 11s. When she warms up, I'm getting around 14.7. I think part of the reason is she's getting cold air from the left front wheel well rather than under hood air, coupled with the huge TSE radiator and 180 degree thermostat. Are my Warmup Enrichment and ASE settings okay?
If I start her when reasonably warm, say sitting in the sun in the parking lot on a cool day when I come out to go get lunch, even if I sit with her idling for a few minutes till the idle drops, the next time I push in the clutch the idle will shoot up to about 2000 for just a second or two, then ramp down.
Thanks and Merry Christmas,
#2
Retired Mech Design Engr
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I'm showing you are on 1.2.0. This has old idle parameters. Update to 1.4.1, the latest, stable release.
There is a discussion here: ms3-basic-firmware-update
It will be worth it to work with the latest stuff, especially as some of your issues are addressed.
I have attached my tune, which has good idle characteristics. Yours may not end up the same, but you can see what are preferred methods to use (MAT for the IAC Initial Values Table, rather than Use Last Value, which is why you are getting the action described in your last paragraph).
There is a discussion here: ms3-basic-firmware-update
It will be worth it to work with the latest stuff, especially as some of your issues are addressed.
I have attached my tune, which has good idle characteristics. Yours may not end up the same, but you can see what are preferred methods to use (MAT for the IAC Initial Values Table, rather than Use Last Value, which is why you are getting the action described in your last paragraph).
#5
I have attached my tune, which has good idle characteristics. Yours may not end up the same, but you can see what are preferred methods to use (MAT for the IAC Initial Values Table, rather than Use Last Value, which is why you are getting the action described in your last paragraph).
Thanks much. Now that I seem to have 1.4.1 running, I plan to compare to your tune page by page.
#6
Boost Czar
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I have three issues. First, if I rev the engine or move the car before the O2 sensor is providing an actual reading, the idle gets all wonky. I have to shut her down, restart and wait. I've learned to live with it, but sometimes, like making room for the next guy to get gas at the track, I'll move the car out of the way, shut her down...etc. Now that I know a little more about EGO Correction, it seems logical something would happen, but is there anything I can do? She has always done that since installing the MegaSquirt.
I'm seeing cold start, cold temp idle AFRs in the low 11s. When she warms up, I'm getting around 14.7. I think part of the reason is she's getting cold air from the left front wheel well rather than under hood air, coupled with the huge TSE radiator and 180 degree thermostat. Are my Warmup Enrichment and ASE settings okay?
If I start her when reasonably warm, say sitting in the sun in the parking lot on a cool day when I come out to go get lunch, even if I sit with her idling for a few minutes till the idle drops, the next time I push in the clutch the idle will shoot up to about 2000 for just a second or two, then ramp down.
#7
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#8
The reason I ask is with the OEM ECU, you jump Pin 10 and GND with the engine running to do idle adjustments.
#9
Here's my tune with 1.4.1. Something is very wrong. See post #134 in this thread https://www.miataturbo.net/engine-pe...7/#post1387176
#10
I have attached my tune, which has good idle characteristics. Yours may not end up the same, but you can see what are preferred methods to use (MAT for the IAC Initial Values Table, rather than Use Last Value, which is why you are getting the action described in your last paragraph).
#11
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2) Since that set-up I have changed my idle PID to use slider only, no "advanced" P, I, or D settings. It is more solid. I also added more % up on the A/C, as that was set before I went to 10 degrees idle advance.
3) The thread you looked at re: setting idle is pretty good. Brain says to never touch the screw. I'd say, if you touch it, Curly's approach is good. You could also just put idle in open loop and command the valve closed, rather than pull the connector. I would also command the timing to 10*. In setting the 750 RPM, use the TS tach, not the one on the car.
4) After setting the screw, if you do so, while still warm, set the min and max on the PWM % for the idle valve. With timing commanded to 10*, idle in Open Loop, command less and less % until the idle stops falling (should go approximately to the 750 you set with the valve set to Zero). That value gets plugged into the Closed Loop Minimum. Then raise the % in steps. As you do so, RPM will climb. When it stops climbing, that is the % value you plug into the CL Maximum. Mine just kept climbing, so I think I just used the value that gave me 4K, as I figure the engine would never need more air than that.
5) Go back to Curly's warm-up and target setting procedure.
6) There is a wizard for setting warm-up enrichment that is pretty good. Remember to have EGO not operating during the procedure. I altered the method by not running in the idle area, but rather setting a target for idle at about 2000 RPM. That got me in a better place on the injectors for setting warm-up. For me, the warm-up curve is not just about idle, but about adding extra fuel in all of the operating areas. That philosophy has proven true in practice.
7) On start settings. I use a heavy priming pulse to wet the intake walls before cranking pulses start. Pretty sure Rev's base maps do as well. Others do not use that approach.
8) I personally like to Incorporate AFR in fueling equation. You do not. To each his own. If you change that, total update of VE will be required.
9) I have not had a chance to look at your tune. Perhaps tonight. However, again, as you will need to make lots of adjustments, I suggest you reset the basics and tune in a methodical manner. Fix MAT correction, zero out Baro, or set it for you altitude, etc before you start re-tuning. Then use VEAL.
10) Even though you tackle some areas one at a time. There is interaction, and so the loops will need repeating.
11) I use Idle VE and Idle Advance. That way, I can distinguish between running in that area vs idling in that area. the differences are minor, but this enables more advance as soon as TPS takes me out of CL Idle.
12) EDIT: And again, I'm not suggesting you use my exact settings, but more the concepts. Exact values are always build-specific.
#16
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you also have a MAT corrections table working against you. it's removing a lot of fuel when the AITs are warm and adding a **** ton when below 50°F. I would zero this out to 100% across and tune it last.
your injector deadtime and voltage % curve is probably the biggest reason youre having idle issue. i think it's set too aggressively. I bet if we look at idle logs we'll see the fuel actually cutting off completely.
using "last value" in idle control is probably the reason for the surge. I like to use initial values table for idle control and carefully tune that table.
your AE values would be better if you tuned accel-pump over the time-based. its the difference between code written in early 2000 vs 2011.
#17
I hope this isn't a stupid question but... if Baro Correction was Off when it was tuned, what difference does it make what default value is in there? There are a lot of other things that are "Off" that have crazy values greyed out.
I'm at work and need to digest the rest of your post at home rather than on my phone.
Thanks much,
I'm at work and need to digest the rest of your post at home rather than on my phone.
Thanks much,
#19
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This is what I've been trying to say. https://www.miataturbo.net/engine-pe...p-91105/page4/ post 111.
Update FW, zero out the crazy stuff, tune in an organized manner.
Update FW, zero out the crazy stuff, tune in an organized manner.