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-   -   Help plz Fuel VE values seem very unique... (https://www.miataturbo.net/megasquirt-18/help-plz-fuel-ve-values-seem-very-unique-97322/)

NASSEX 06-26-2018 04:13 PM


Originally Posted by 1RMDave (Post 1488466)
It starts good at any temp. I just ran auto tune on warmup enrichment once.

/me *Thumbsup*

NASSEX 06-26-2018 04:16 PM

So all you guys or gals think I should do is just dial in the shape of the VE Fuel table, and dial in warm up enrichment some perhaps?
That's what I'm gathering!! Thank you all so much so far.

Did you interpret anything from the log and tune i sent? That might be strange or is it hard to say? Mainly basic settings I'm hoping to verify are correct for my setup.

1RMDave 06-26-2018 05:16 PM

Ya dude, sounds like you are ready to get started. Dial that thing in!

lsdlsd88 07-01-2018 12:31 PM


Originally Posted by nitrodann (Post 1488445)
You can half your REQ FUEL and then double all of the fuel table numbers and the car will run the same. Absolute VE numbers arent as important as the shape of the table.

I'm not quite following this line of thought. REQ FUEL has a very specific and scientific meaning, is the amount of PW required to get stoichiometric AFR assuming a VE of 1, or 100% if you prefer, at "standard" conditions of IAT and CLT, 100kpa, correct voltage and fuel pressure, and so on.

now, if your car needs 100 VE at idle rpm, you have 2 options: you have a magic intake and 2 magic camshafts that bend fluid dynamics laws, or your injectors characterization is OFF by a mile.

NASSEX 07-02-2018 12:41 AM


Originally Posted by lsdlsd88 (Post 1489258)
I'm not quite following this line of thought. REQ FUEL has a very specific and scientific meaning, is the amount of PW required to get stoichiometric AFR assuming a VE of 1, or 100% if you prefer, at "standard" conditions of IAT and CLT, 100kpa, correct voltage and fuel pressure, and so on.

now, if your car needs 100 VE at idle rpm, you have 2 options: you have a magic intake and 2 magic camshafts that bend fluid dynamics laws, or your injectors characterization is OFF by a mile.

I set the injector dead time based on what I seen on flowforce's website. But it didn't feel like I was really putting in anything unique to my application. Except for the fact that I am using their product :S Felt a little too easy. Is it likely that I put the wrong information in there? Or should I say maybe mine isn't as dialed in as it needs to be?

I did the same exact thing to fill in the Battery Voltage Correction(ms/v). Just used what flowforce has posted on their website. I got the 640cc flow force Miata injectors in case that helps.

http://www.flowforceinjectors.com/instructions/ ps, like I said, only info I added to megasquirt was REQ FUEL estimate based off the size of engine, injector size in cc, etc, and I used the battery voltage correction & injector dead time just from their website on that page. Should that be enough? Or am I messing something terribly up?

But as for "PWM Current Limit(%)", "PWM Time Threshold(ms)", and "Injector PWM Period(us)", I would like to fill those fields out IF it's important (which I think it is) except I'm running sequential. Because it is what was chosen on the base map I started with. Aren't those former fields supposed to only be for batched?
I'm new to this, but I learn fast. I'd MUCH rather do things right and not have to learn this the hard way. All insight and knowledge is highly appreciated. Cannot stress that enough

nitrodann 07-02-2018 01:09 AM

The ones on the FF website dont plug directly into MS, so make sure you used the right values.

Dann

NASSEX 07-02-2018 03:55 PM

Would you be able to help me out with that please? Or do you know a general guideline that I could follow to figure it out for myself. That could be my problem. Appreciate you

Because right now my idle values are in the high 90's 95's and the 7-8psi boost (140kpa) range of the table, I'm looking at 160 and higher for values to maintain reasonable AFR target. I know something is off.

NASSEX 07-02-2018 04:26 PM


Originally Posted by lsdlsd88 (Post 1489258)
I'm not quite following this line of thought. REQ FUEL has a very specific and scientific meaning, is the amount of PW required to get stoichiometric AFR assuming a VE of 1, or 100% if you prefer, at "standard" conditions of IAT and CLT, 100kpa, correct voltage and fuel pressure, and so on.

now, if your car needs 100 VE at idle rpm, you have 2 options: you have a magic intake and 2 magic camshafts that bend fluid dynamics laws, or your injectors characterization is OFF by a mile.

How should I edit my injector characteristics for a 640cc Flow-Force Miata injector being installed on a MS2. TunerStudio v3.0.28
1994 Mazda Miata 1.8l BP...

Not sure if it's relevant but here's some info that I have on a card that the injectors came with.
Flow rates (cc/min, gasoline)
Injector #1 static: 661 2ms pulse: 30.7
Injector #2 static: 660 2ms pulse: 30.6
Injector #3 static: 661 2ms pulse: 30.6
Injector #4 static: 662 2ms pulse: 30.7

Currently my REQ_FUEL is what it should be, going from stock 1.8 injectors.
The injector dead time is 1.120@ 13.2v
Battery voltage correction is 0.144.

What other characteristics do I need to change?

Note: For anybody new to the thread; You do not have to read over any of my earlier posts. They are all practically saying this same thing.

NASSEX 07-03-2018 11:32 PM

Update
I've rented a fuel pressure tester from Autozone. If I have some free time tomorrow night, I'm going to test fuel pressure at idle, cruise and WOT. It could definitely be in fact the reason why the VE numbers are so high during idle. and through out. One of my major fears is overworking the injectors. They were a pretty penny out of my wallet.

irodd 07-04-2018 11:30 AM

Your Idle Valve Closed duty 5% and Open Duty 23%.
looks unusual

NASSEX 07-04-2018 05:48 PM


Originally Posted by irodd (Post 1489793)
Your Idle Valve Closed duty 5% and Open Duty 23%.
looks unusual

Thank you so much for spotting that.

Is that controlled by a setting or is it a reading, based on hardware signal output? Like for example, I'm pretty sure that the idle control valve air hose is kinked pretty bad. I was eventually going to put a better hose there to fit it properly and not have it kinked/restricting flow.
Do you think it's possible the hose that is causing the duty numbers or is it also a setting on tunerstudio?
Thanks

ps. I'm going to still be running the fuel pressure test in an hour or so.

irodd 07-04-2018 06:26 PM


Originally Posted by NASSEX (Post 1489838)
Is that controlled by a setting or is it a reading, based on hardware signal output?.

Should be the settings based on the idle valve test.
You mentioned you use DIY basemap for 94-95 1.8L Miata from megasquirtpnp.com, take CL settings from that basemap too

NASSEX 07-04-2018 07:02 PM

When I load up the basemap just to check the idle settings
It's originally setup to run open-loop (warmup)
PWM valve (2 or 3 wire)

Not sure why or even if I had it changed to open loop but when I switch the base map over to closed loop, it has:
Idle Valve closed Duty 5.9
Idle Valve Open Duty 23.5.

So that's what it has on the base map as default.

Edit: Small side question, Could me venting the PCV valve opening straight to atmosphere with no pcv valve at the moment possibly be causing this? - I'm going to re-install the pcv valve temporarily to see if it might fix it. Along with the fuel pressure test if I get enough time to try it before the fireworks tonight.

irodd 07-04-2018 08:41 PM

Enter the settings from DIY basemap and start the car

https://cimg6.ibsrv.net/gimg/www.mia...c1c075e549.jpg

NASSEX 07-04-2018 10:53 PM

PCV valve did not make a difference as I kinda figured.
Fuel pressure is average. idle = 32psi


Enter the settings from DIY basemap and start the car
Thank you!! I am going to try that right now.

Happy 4th of July everybody!

NASSEX 07-04-2018 10:56 PM

NEVERMIND! My mistake. It should still work, they're the same values just slightly named different.

I'll report back with whether or not this helps.
I might have to try it tomorrow morning. It's getting pretty late tonight

NASSEX 07-05-2018 12:05 AM

6 Attachment(s)
I tried the changes and it didn't do anything. But I will keep them. because it does idle pretty good.

Quick question: Am I supposed to have the throttle blade fully closed via the screw input in order to tune idle fully with megasquirt? Or not?

I just wish I knew what was causing the high VE numbers. Very afraid of overworking the injectors. What could be causing this? Is there a way to check if the injectors are working harder than normal for idle?

I uploaded my most recent tune. Literally.
Attachment 221151
And took several logs of idle. These DataLogs are of the current tune that I'm running just above. They're all short logs of idling about 20 minutes ago.
Attachment 221152
Attachment 221153
Attachment 221154
Attachment 221155
Attachment 221156

NASSEX 07-05-2018 12:29 AM

PW values for 2 out of 4 injectors, missing? o.O

Does THIS mean I've been running on 2 cylinders this whole time?!!!

jk idk. Well I checked the duty cycle 1 & 2 numbers on some of my boosted pull logs and it seems to never go higher than 40 at the max. So should I just rest assure that I'm probably not overworking anything? From my high VE table numbers =\

https://cimg2.ibsrv.net/gimg/www.mia...15647dcd66.png

irodd 07-05-2018 06:30 AM

Nice arrows!

NASSEX 07-05-2018 12:21 PM


Originally Posted by irodd (Post 1489884)
Nice arrows!

thx lol
​​​​​​​I think my innector dead time is a little too low maybe


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