Steve's Megasquirt/tunerstudio Help Thread

FastDriver

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with incorrect corrections in these tables you should see....
A lean tip in that eventually tapers down to main fuel enrichment.
That's exactly what I'm seeing.

Ie. You should start lean and then richen up, this is tuned SD correct? If so the 've table should take over fueling directly after the transient event (throttle increase).
Yes on all counts.

-Your pumpshot setting is the same as a tps based enrichment, rule of thumb set this to twice your idle pw value for right off idle (left side of the table) and quadruple at the top (right side of table)
Thanks for that rule of thumb. I'm way off, then. I think base idle PW is around 1.2-1.4 ms. You can see in my table above that I'm going from .99 on the left up to ~2 on the right. I'll try your recommendation. I'll double check idle's gross pulsewidth and double it on the left, quadruple it on the right, and interpolate in between. Then try and tweak from there.

The rest of the settings look like map based acceleration enrichment settings, I don't even have these enabled in my tune file, after the tps based enrichment my 've table takes over for fuel. Usually I choose to use one type or the other to tune from (tps or map based ae) some setups work well with a blend of both although I have never tuned this way.
Thanks. Another good tidbit. TPS seems relatively straight forward to mess with. I have a feeling I'll see the dMap enrichment table showing up most obviously when I power-shift the car since there will be no TPS delta and the MAP should be all over the place at that point.

Now with all that said, you should still be able to get a maintained rich (or at AFR taeget) fuel with all of these turned off from the main fuel table.
These settings are to correct lean tip in only.
Lean tip in is exactly what I'm trying to solve. Possibly unless I make the main tables super rich at steady-state, there's nothing I can do from there to stop what I'm seeing at tip-in. Thank you again, man.

Chris
 
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a91what

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That's exactly what I'm seeing.



Yes on all counts.



Thanks for that rule of thumb. I'm way off, then. I think base idle PW is around 1.2-1.4 ms. You can see in my table above that I'm going from .99 on the left up to ~2 on the right. I'll try your recommendation. I'll double check idle's gross pulsewidth and double it on the left, quadruple it on the right, and interpolate in between. Then try and tweak from there.



Thanks. Another good tidbit. TPS seems relatively straight forward to mess with. I have a feeling I'll see the dMap enrichment table showing up most obviously when I power-shift the car since there will be no TPS delta and the MAP should be all over the place at that point.



Lean tip in is exactly what I'm trying to solve. Possibly unless I make the main tables super rich at steady-state, there's nothing I can do from there to stop what I'm seeing at tip-in. Thank you again, man.

Chris
glad i could help some,
 

a91what

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Hope all is well. Just making sure you all got my last post. Thanks
That is much better the log has usable information! now first thing we have to do is settle that oscillation in the idle down. it is down right terrible... hopefully this new tune will help some please grab a log like usual for me and we can move forward.
 

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Feb 6, 2012
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That is much better the log has usable information! now first thing we have to do is settle that oscillation in the idle down. it is down right terrible... hopefully this new tune will help some please grab a log like usual for me and we can move forward.
Thanks. Still some oscillation. Ran ok on cold start. Had to hold the accelerator down upon start. Runs erratic when the car has warmed up and restarted.
 

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a91what

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Just so we are on the same page, you are loading the tune file I send and making no changes to it right.... The tune I sent last time had closed loop idle control, but your log file showed open loop [warm up] idle control being used... but the tune file you sent with the datalog does show closed loop idle still set.
If you did have to make the change to get the car to run that is fine but I need to know so I can do something about it on this end.

This new tune file is being sent with open loop idle control, I set the numbers so that it will purposely idle high. once you get the log I need to adjust fuel from [that's all I'm doing right now is adjusting fuel] Feel free to play with the idle settings until the car idles well warm. then save that tune and send it my way. If you have to hard a time doing this on your own I can do it from this end it will just take me a few tries as I cant see the immediate change the setting I input make.

What time zone are you in? I am east coast so if need be I can even remote in one night over wifi and take control of your computer and tune the car live.
 

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bird_dog0347

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Hey guys, I'm back from the dead after more than a year of not driving the car. I haven't really played with the tune much since 2016 but now that I'm ready to drive it again I've gotta get a few things squared away.

So previously when I would drive it I was having cooling issues that I believe to be resolved now with a better radiator, and MK VIII electric fan. The other big problem in drivability is when it starts up I have to keep blipping the throttle until my LC2 WB O2 sensor comes fully online and is reading the real AFR. If I don't, the car will die, but once it's reading the AFR it all seems to run ok. I've got WUE configured but the car doesn't high-idle on a cold start like I would expect (like my 2014 GT for example) so I don't know if that's in the tune or throttle body/IAC related. It still has the stock throttle body for now, I plan to put on a 70mm Accufab in the next few months.

Engine details are TFS 170 heads, 1.7 roller rockers, TFS Stage 1 cam installed dot to dot (didn't have degree tools), tubular GT40 intake with ported lower, 19lb injectors, stock TB, it still has the stock MAF but disconnected as my CAI was the LMR unit and I don't want to put my filter in the engine bay. It has long tube BBK headers, BBK H pipe with flowmaster cats installed in it and flowmaster cat back. As mentioned it has the SVE radiator, Mk VIII fan and DCC controller. It's a T5 trans and 3.55 gears in the rear.

Attached is the tune and a luke warm start and idle from just now. If anyone can help me with the startup issue first that would be awesome, then after that let's look into why it feels way slower than I think it should be.

Thanks in advance!
-Nick
 

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a91what

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Hey good to see you back, since you have a good start i will give you some pointers and then once you try them i can help you adjust the tune if you need me to.

The cold start issue, likely it is a coincidence that when the WBO2 comes up it goes away, try adding fuel in the afterstart enrichment and lengthen the time. IMHO multiply both tables by 1.1 ( this will add 10% to both fields) start here and see if it helps.

The lack of a high idle on startup is likely caused by the idle settings, i do not have my tuning laptop with me [work] so i will have to look at them later for you to give any advice here. As long as the idle is stable once fully warmed up this should all be fairly easy to fix. The main thing to remember is to make one change at a time and see how the car reacts to it.
 
Feb 6, 2012
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Just so we are on the same page, you are loading the tune file I send and making no changes to it right.... The tune I sent last time had closed loop idle control, but your log file showed open loop [warm up] idle control being used... but the tune file you sent with the datalog does show closed loop idle still set.
If you did have to make the change to get the car to run that is fine but I need to know so I can do something about it on this end.

This new tune file is being sent with open loop idle control, I set the numbers so that it will purposely idle high. once you get the log I need to adjust fuel from [that's all I'm doing right now is adjusting fuel] Feel free to play with the idle settings until the car idles well warm. then save that tune and send it my way. If you have to hard a time doing this on your own I can do it from this end it will just take me a few tries as I cant see the immediate change the setting I input make.

What time zone are you in? I am east coast so if need be I can even remote in one night over wifi and take control of your computer and tune the car live.
Guarantee you I have not made any changes to what you have sent nor would I without your consent. Trusting your expertise. Did a new run.Car starts up good. Idles a little high as you said. If you need to do a remote I am available whenever you need. Just say when. Thanks
 

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bird_dog0347

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Hey good to see you back, since you have a good start i will give you some pointers and then once you try them i can help you adjust the tune if you need me to.

The cold start issue, likely it is a coincidence that when the WBO2 comes up it goes away, try adding fuel in the afterstart enrichment and lengthen the time. IMHO multiply both tables by 1.1 ( this will add 10% to both fields) start here and see if it helps.

The lack of a high idle on startup is likely caused by the idle settings, i do not have my tuning laptop with me [work] so i will have to look at them later for you to give any advice here. As long as the idle is stable once fully warmed up this should all be fairly easy to fix. The main thing to remember is to make one change at a time and see how the car reacts to it.
I tried to increase the ASE but it already seemed pretty high to me as a percentage so I went up 5 in a few cells where it would take effect given the temps, no change good or bad.
 

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a91what

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A remote in would be the fastest way to get the idle set correctly. lets try one more blind tune run if we do not have the idle pinned down by then i will do a remote in.
 

a91what

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I tried to increase the ASE but it already seemed pretty high to me as a percentage so I went up 5 in a few cells where it would take effect given the temps, no change good or bad.
i will have to look at the log file to see what the timing is doing at startup, oscillation could be caused by many things including...
-overly rich condition on startup
-lean on startup
-idle speed too low on startup
-timing low, timing high, or timing oscillating at startup.
 

bird_dog0347

I really enjoyed seeing your rear end up close
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i will have to look at the log file to see what the timing is doing at startup, oscillation could be caused by many things including...
-overly rich condition on startup
-lean on startup
-idle speed too low on startup
-timing low, timing high, or timing oscillating at startup.
Thanks Steve, sounds good.
 

a91what

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Mod Dude
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Thanks Steve, sounds good.
Found a bit of time to make some changes, based on the build I assume no boost correct how about in the future??

Try this and let me know, if the idle wont settle down change it back to "warm up" in idle settings and let me know what you needed to do.
 

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5.0Thunder

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Thanks in advance!
-Nick
So far I see that you don't have "incorporate AFR" turned on and the datalog shows you're pegged rich for about 45 seconds. Is this how long the LC2 takes to get going? I was going to say you may have too much ASE and WUE but I can't say that with certainty if the wideband isn't active during that time. Are you able to have the wideband turn on and get ready before cranking (like with constant 12v power) to get your startup tuned better, then switch back to normal wiring? I do see that after the 45 seconds, the wideband jumps right up to stoich, which is kind of odd for a couple of reasons.

EDIT: Looks like Steve got you another tune to try. I'll let him take it on.
 

bird_dog0347

I really enjoyed seeing your rear end up close
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Found a bit of time to make some changes, based on the build I assume no boost correct how about in the future??

Try this and let me know, if the idle wont settle down change it back to "warm up" in idle settings and let me know what you needed to do.
Thanks, I'll give it a go. No boost and no plans for boost.
 

bird_dog0347

I really enjoyed seeing your rear end up close
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Ok, got it loaded and started it up... not sure which change did it but now I have a high idle that slowly decreases as the temp comes up as I would expect. There's some surging during the warm up in about the last half of the warm up period but once it settles in it's all good. It does seem to have more power now too, but I only took it around the block after the warm up just to see how it drives. Huge thanks Steve, it seems like the car will actually be usable now. Here's the data log from the whole thing.
 

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a91what

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Mod Dude
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Great! I will look at the log file for you a bit later on
Guarantee you I have not made any changes to what you have sent nor would I without your consent. Trusting your expertise. Did a new run.Car starts up good. Idles a little high as you said. If you need to do a remote I am available whenever you need. Just say when. Thanks
I have not forgotten about you, I am going to be busy all weekend so when i get the chance i will shoot you a new blind tune from the datalog you sent. Like I said before if it does not clear the idle issue up i will need to do a remote in. It may be fairly late at night when i have time to help with a remote in. Im on the east coast so maybe 8 or 9 pm... i will need the car fully warmed up when i take over from there it should only take 10 mins or so to do my thing.