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-   -   Changing Idle Fuel, AFR isn't moving. (https://www.miataturbo.net/megasquirt-18/changing-idle-fuel-afr-isnt-moving-83975/)

Schuyler 04-16-2015 05:32 PM

Changing Idle Fuel, AFR isn't moving.
 
4 Attachment(s)
So, my idle is terrible. After changing to the new deadtimes from nigelt, it is BEYOND terrible. I started tuning it today, and am bewildered. I set the idle valve manually so it stayed in one place, and finagled with it until it was in the center of a square. Changed the fuel. Nothing happens. Changed it more, nothing. I added 30 fuel for shits and giggles, nothing happened. Idle VE was enabled, I saw the light. So I turned off VE Idle and did the same thing to the VE Table, same result. Any ideas as to what I might be missing that is causing this? It is an actual AFR reading, not like just sitting pegged. ~17.5:1.

Tune, which don't hate. I set VEAL on easy and have driven once, so it is sloppy as of now. Log is just me letting the car idle as she sits currently. Warning: It's bad.

DNMakinson 04-16-2015 10:03 PM

Watch more Star Wars.

aidandj 04-16-2015 10:24 PM

What happened to Schuyler? Who did he anger?

Edit: Star wars is taken vary seriously by JoeP

DNMakinson 04-17-2015 06:57 AM

Actually, I understand it was Steve (SixShooter). Schuyler should be back soon.

I have only opened the msq on a new TS install, so I'm not sure all of the parameters were picked up correctly. It could also be a FW version conflict. My ignorance is showing. I'm seeing all of the CL idle PID parameters at weird values. If those are real, that could be the issue.

*EDIT* Your pulse widths seem high to me for the injector size. I idle at about the same PW, and my inj should actually have greater dead time. So, with your inj and PW, I would expect you to be rich, not lean.

Last try: Could it be the same bad PCV valve that pops your dipstick (Realize that has not been confirmed) leaking in the other direction? OK, how to say, "pops your dipstick" without saying "pops your dipstick".

Schuyler 04-17-2015 09:22 PM

7 Attachment(s)
haha it was my boy JoeyP. As it turns out, he takes his StarWars QUITE seriously. So I uh, totally watched it them during my 24 hour ban. Totally. Without a doubt.

The TS install on my new desktop sucks. Having a lot of issues, one of which keeps me from opening anyone elses tunes. I can still do that on my surface though.

I don't think the PCV valve is the issue, as it being open/closed shouldn't effect idle any right? It's supposed to be open during idle, but if it wasn't, I don't see it hurting anything.

Here are the closed loop values and some other tables so you can see without opening the tune. Ignore the rough VE Table, I'm still running VEAL on easy with these new deadtimes.

EDIT: And David, let me know if those PID values look wrong, because they're yours :P So if that's the case, it may indicate our tunes do not like being opened in one another's TS. Except for the sensitivity. I lowered that hoping to reduce hunting after it had already started.

https://www.miataturbo.net/attachmen...ine=1429320171

https://www.miataturbo.net/attachmen...ine=1429320171

https://www.miataturbo.net/attachmen...ine=1429320171

https://www.miataturbo.net/attachmen...ine=1429320171

https://www.miataturbo.net/attachmen...ine=1429320171

https://www.miataturbo.net/attachmen...ine=1429320171

(3deg pulled in boost during initial retune)

https://www.miataturbo.net/attachmen...ine=1429320171

DNMakinson 04-17-2015 10:57 PM

I loaded the TS with an old .ini file. I'll have to try to load the current one, or move your msq to my other computer.

That is the flattest VE table I've ever seen. I'd expect it to make sense only if you were using a rising rate FPR. Bottom rows should be in the 40's not 80's.

I hope an MS expert comes in soon.

Erat 04-18-2015 08:02 AM


Originally Posted by DNMakinson (Post 1224510)
Bottom rows should be in the 40's not 80's.

Why?

DNMakinson 04-18-2015 08:44 AM

Because, he is running a non-referenced FPR on a non-return fuel system. I was going from memory, and maybe 40's is a little low (though mine are); nonetheless, it does not make sense to me to have the same VE at idle kPa and below, as at 100 kPa.

Is your experience different?

*EDIT* Let me say it another way. The idea of Speed Density, that is the main driver of pulse length in the fueling equation is the VE, which is driven by the table.
The table looks at Speed (RPM on horizontal axis) and Density (inverse of the MAP on the vertical axis). At a given RPM, the amount of fuel needed is determined by the amount of air ingested. This is presumed to be determined by MAP. The higher the kPa, the more air that is drawn / pushed into the cylinder, and therefore the more fuel that will need to be given.

So to have the same VE at 100 kPa as 30 kPa is to be telling the system that the engine is ingesting the same mass of air under both those conditions. We all know that is not the case.

Now it is also true that when under vacuum, and a non-manifold referenced fuel rail, there is more differential pressure across the injector. So, at 45 kPa, the injector will flow more fuel than at 100 kPa MAP. Again, lower VE is called for at lower kPa. This is a smaller effect.

So I said that having a Rising Rate would flatten the curve because it would increase fueling disproportionately to MAP, reducing the need for the VE to rise with MAP in the table. That is not the case here.


OK, Ignore that. MAP is also in the fueling equation :loser:

Table looks flat to me, but perhaps I'm reading too much in to that.

Braineack 04-18-2015 09:05 AM

why is you dual fuel idle ve table active?

Braineack 04-18-2015 09:07 AM

what firmware are you on? why cant TS find it?

DNMakinson 04-18-2015 09:12 AM


Originally Posted by Braineack (Post 1224535)
what firmware are you on? why cant TS find it?

I had loaded a new TS on my work computer. I don't know how to get the .ini. file from the Megasquirt files, to be compatible with 1.3.4 F;, because at home, whenever I go to new FW, the computer picks up the .ini over the interweb. Could use some advice.


Schuyler: Have you verified the correctness of the new dead times with Lars or others? I'm presuming the new value is shorter than the old, and your problem got worse.

shuiend 04-18-2015 10:30 AM


Originally Posted by DNMakinson (Post 1224536)
I had loaded a new TS on my work computer. I don't know how to get the .ini. file from the Megasquirt files, to be compatible with 1.3.4 F;, because at home, whenever I go to new FW, the computer picks up the .ini over the interweb. Could use some advice.


Schuyler: Have you verified the correctness of the new dead times with Lars or others? I'm presuming the new value is shorter than the old, and your problem got worse.

I have not tried the new dead times yet.

Braineack 04-18-2015 12:51 PM

so what firmware are you running?

1.3.4 f? wtf is that?

DNMakinson 04-18-2015 01:28 PM


Originally Posted by Braineack (Post 1224578)
so what firmware are you running?

1.3.4 f? wtf is that?

That would be the MS 3 FW version, well, ignore the "f". I don't know where that came from. 1.3.4 MS3.

The TS is the latest, so should be 2.6.18


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