Who here is using PE on E38 PCM to disable closed loop idle with large Cams?

[LS ROB]

Hey guys, I just double checked it and it is there. It seems to be the way you view the MAF table? Whenever you click on the MAF table, view the main file, then the compare file, then "show differences." That's where it shows up.

[Cringer]

if u set the makeup to ''none'' and then zero out the makeup tables do u then have to adjust the degrees that was allocated for the makeup back into the other eoit settings so they stay the same or does it not affect them ?

Yes you are absolutely correct. I did leave out that detail which might throw some people off if then want to make a quick test, so thank you for pointing that out! Assuming your SIOT is correct, or you want to preserve it for an apples to apples comparison...

If you turn Makeup Mode off, then you would need to ADD 30 degrees (or whatever value is in the Makeup ECT table) to the Normal ECT table.

Then if you want to change it back by setting Makeup Mode to Single or Multiple, you would need to SUBTRACT that 30 degrees from the Normal ECT table and recreate the Makeup ECT table as needed (if you zero'd it out).

[Cringer]

Hey guys, I just double checked it and it is there. It seems to be the way you view the MAF table? Whenever you click on the MAF table, view the main file, then the compare file, then "show differences." That's where it shows up.

I am not able to replicate that. If you open my file and go into Edit > View Change/History Logs and look on the Complete Saved Logs tab you will see the newest entry from me only changing the injector fields. Not sure if that timestamp is hardcoded or will change due to timezones. I would be curious what you see. But the yellow time is what I changed, and the green time is whatever was last done prior to me. You might need to open the first file too to make sure that timestamp matches. I am guessing either you accidently changed it, or possibly the file was corrupted at some point (but that is a long shot). What version of VCM are you on? I am using 5.0.4.


it wasnt me.jpg

[LS ROB]

I am not able to replicate that. If you open my file and go into Edit > View Change/History Logs and look on the Complete Saved Logs tab you will see the newest entry from me only changing the injector fields. Not sure if that timestamp is hardcoded or will change due to timezones. I would be curious what you see. But the yellow time is what I changed, and the green time is whatever was last done prior to me. You might need to open the first file too to make sure that timestamp matches. I am guessing either you accidently changed it, or possibly the file was corrupted at some point (but that is a long shot). What version of VCM are you on? I am using 5.0.4.


it wasnt me.jpg

Interesting. A while back, I noticed this on one of my personal files as well with the MAP linear/offset settings. Thought it was just a fluke, but apparently I have something going on?? I'm on 5.0.4.

[Allen Vos]

I did the best I could with the log you sent, I whish it had more IPW vs RPM data at hand. The tune I sent is going to be a rough start based only on ideal valve events. Flash it and log it and then the real EOIT tuning begins. I have also attached a pic of the EOIT graphing out the setup I gave you calling the specific areas of interest as detailed in the following text.


We will start at idle.
EVC is 394
SOIT is 385
We are gambling (spraying early) by 9 degrees and hoping no fuel short circuiting occurs.
Try this first and log obviously. Then create two new tunes altering the Normal ECT table by changing the 85 to something of your choosing. Maybe start with 3 degree increments, make a tune with 88 (spraying earlier at 388) and one set to 82 (spraying later at 382).

I also turned off the Make Up Mode because I don't like it. I urge you to experiment on NONE, SINGLE, and MULTIPLE to see what the fuel trims do.
My theory is this...and this is based on the logs I captured...turning this off forces all the fuel to be sprayed in one large shot at the beginning of the induction cycle which has two main benefits.
1) Most importantly it gives the fuel more time in the cylinder to tumble, swirl and mix with the air which translates to less chance of misfire, less chance of detonation, more complete combustion. So it is safer, reduces fuel consumption, and emissions.
2) By spraying early you give the fuel more time to work its magic through latent heat of vaporization. That is, fuel cools things down...which means a denser air charge = more power, and less heat = less chance of detonation.
I do not expect that this effect is huge, however, it is not negligible either and when it comes to pushing equipment to its limits safely, I will take every fractional percent I can get.

Sweating the details of reversion (this is covered at the end of my first EOIT video, not the tool demo/how to video), my pet theory...
I have set the EOIT to 470 so that no matter what, fuel is not sprayed "in the danger zone" of getting reversed. IVC is 610, BDC is 540, 610-540 is 70. So 540-70=470. We don't want any fuel sprayed during the transition of the piston transitioning between intake and compression with the intake valve open. Hard to explain via text, but there is a graphic in the video that should clear this line of thinking up.


Mid RPM's (1,700 - 2,500)
This is where you will most likely need to experiment to see what your setup needs. Right now 2,048+ RPMs is where we see the first sign of changing the SOIT. It is a fine line here. We are still in danger of short circuiting the fuel by spraying too early. You will defiantly need to experiment with the SOIT here (both moving the Boundary Angle and Normal RPM). I like to have all my mid-RPM spraying done right before, or as close to, peak piston velocity as possible to get the fuel in right before the violence can mix everything up just right.


High RPM's
This is where everything changes and I wish I had a dyno to test things. I set my EOIT to occur 30 degrees before the IVC. IVC is 610, so EOIT for you is 580.

Most injectors are going to have such a long pulse width in comparison to the injection window that there is no choice but to spray on the back of the closed intake valve. This is not necessarily bad when you consider the violence that happens here at peak horsepower. Fuel will be sitting in a puddle on the closed valve. The valve starts to open. The piston is still moving up and breaking over TDC...so the intake stroke has not technically begun and once the piston breaks over TDC the vacuum signal it is creating is lack luster as piston velocity is slow and lazy. But what we do have working for us is the overlap in combination with the vacuum from the exhaust, which jolts the induction cycle into life! That puddle of fuel is sucked into the chamber with great force and atomization factor 360 degrees around the valve margin...perfect annular flow. This puddle (most likely) is going to be the majority of your fueling during PE, the remaining bit is topped off at the end. Not a lot of air is moving into the cylinder during the last 30 degrees either...and if normal cam lobes are in play (which they are) we are in sub .050" lift and we are going to be hitting the back of the intake valve as it closes any way.


So in summary...
1) For CL operations, focus on SOIT
2) For PE operations focus on EOIT

Attachment 141555

Thank you for the detailed explanation on this, its much appreciated.


I can see what you did on the idle with the SOIT at 385* and the EVC at 394* and then the end of injection at 470*.

So this gives the total window of injection at idle within 85* of crank revolution.

I see your formula for figuring out the EOIT for 470*, and yes it makes perfect sense to me.

Is this a standard formula for any engine to figure out EOIT for idle and is it in your EOIT assistant?


I flashed your EOIT settings to the ECM today. It seemed to fire up and idle well. I feel it didn't smell as much which is a bonus.

However at idle it ran a bit leaner than using the stock EOIT settings, then it threw the check engine lite for O2 sensors to lean on both banks. So it might be possible we have fuel

short circuiting out the exhaust valve so I will need to play with the SOIT settings a bit like you had mentioned.

I made a log which I will share here. I've added some IPW and ECT to the log and revved it up periodically so hopefully there is a bit more data than on yesterdays log.

One thing I did notice is my O2 sensor on bank 2 seemed to be staying lean quite a bit more than Bank 1, but would respond and go rich as soon as the throttle was given a quick blip.

It was staying lean on yesterdays log too, so this should have nothing to do with EOIT settings.

I'm not sure what's causing this unless maybe my sensors are starting to deteriorate, and was thinking it might not be a bad idea to get a new pair of O2's just to be safe.

Fuel trims were extremely high at idle, 24% LTFT and like 15% STFT

But, by all means check the log out and tell me what your thoughts are.

Keep in mind I have made no changes to the VVE or MAF yet and I wont have a wide band until the end of this month, so I am limited as to how much I can do until this happens.

I still need to alter the O2 settings for the idle and I seem to agree with LSROB that this thing simply just needs more fuel at idle to not run so lean.

Is it possible to add some fuel in at idle only without the wideband so this thing is not running so lean?
Attachment 141604

[Allen Vos]

I completely forgot to mention I do have long tube headers on the car so the O2's are farther from the cylinder heads than with stock manifolds and its prolly worth mentioning I run the stock fuel injectors for the LS3

[Alvin]

How many of you guys are turning on PE at idle to force open loop on a large cammed engine to keep it from over fueling and drowning itself?

How are you guys doing this?

I have an LS3 with a TSP Stage 2 Cam 229/244 .629"/615? 112 LSA, 109 ICL

I have long tube headers with an off road x pipe and rear O2's deleted and turned off.

I am using both MAF and VVE tables for tuning.

I have got the car fired up and running fine with a very stable idle at 800 rpm


However you can literally watch the fuel trims go positive and continue to add fuel making it terribly eye burning rich and if left to idle long enough will load up and misfire.

So I would like to run this thing in open loop up to around 1000 rpm and then have closed loop take over for normal driving.

Is there any other options to do this or is PE the only way to force open loop at idle?

I used to do this a long time ago.. I stopped and can't really remember why.

I'd suggest you do this in strictly SD first. The MAF can cause the issue you are describing just as much as trying to run closed loop with a bigger cam. That cam should do OK in closed loop. Its on the edge of what works but it should be ok.

Cam reversion hits the MAF sensor pulling air in and out.. so like a double dip in airflow measurement. It's too noisey to use with a larger cam like this.

Honestly, the VVE doesn't look appropriate for the cam. Like you still have work to do on it.

Lastly, Rich cars stink sure.. but lean cars are the ones that really burn your eyes.

[Cringer]

Thank you for the detailed explanation on this, its much appreciated.


I can see what you did on the idle with the SOIT at 385* and the EVC at 394* and then the end of injection at 470*.

So this gives the total window of injection at idle within 85* of crank revolution.

I see your formula for figuring out the EOIT for 470*, and yes it makes perfect sense to me.

Is this a standard formula for any engine to figure out EOIT for idle and is it in your EOIT assistant?


I flashed your EOIT settings to the ECM today. It seemed to fire up and idle well. I feel it didn't smell as much which is a bonus.

However at idle it ran a bit leaner than using the stock EOIT settings, then it threw the check engine lite for O2 sensors to lean on both banks. So it might be possible we have fuel

short circuiting out the exhaust valve so I will need to play with the SOIT settings a bit like you had mentioned.

I made a log which I will share here. I've added some IPW and ECT to the log and revved it up periodically so hopefully there is a bit more data than on yesterdays log.

One thing I did notice is my O2 sensor on bank 2 seemed to be staying lean quite a bit more than Bank 1, but would respond and go rich as soon as the throttle was given a quick blip.

It was staying lean on yesterdays log too, so this should have nothing to do with EOIT settings.

I'm not sure what's causing this unless maybe my sensors are starting to deteriorate, and was thinking it might not be a bad idea to get a new pair of O2's just to be safe.

Fuel trims were extremely high at idle, 24% LTFT and like 15% STFT

But, by all means check the log out and tell me what your thoughts are.

Keep in mind I have made no changes to the VVE or MAF yet and I wont have a wide band until the end of this month, so I am limited as to how much I can do until this happens.

I still need to alter the O2 settings for the idle and I seem to agree with LSROB that this thing simply just needs more fuel at idle to not run so lean.

Is it possible to add some fuel in at idle only without the wideband so this thing is not running so lean?

Attachment 141578

The EOIT Assistant won't give you answers or suggest what you should do. It just makes visualizing and understanding the EOIT tune with relation to cam events easier. You are the tuner and need to know how to do it. This is why I made the first EOIT video as it goes into the theory.

I am not able to open that log attachment, it says invalid file.

But as of now I cannot use the subjective feedback that "fuel trims are higher" because you also stated "I have not tuned MAF or VVE". I would also suggest disabling LTFT, at least for doing this detailed tuning, if not permanently. Additionally, to cut through the EOIT vs fuel trim issue, you really need to look at the injector pulse width. And even then, the reported IPW does not include the modifiers related to short pulse adder, IPW vs Voltage, etc. So you can really look at the raw number.

My suggestion is to use the initial settings I sent. Then do your due diligence on tuning MAF and VVE and idle to get it dialed in as close as you can. THEN start messing with EOIT and see how that changes the fuel trims. As a sanity check you can even use the stock settings.

Question: is there a reason you changed [ECM] 275 - Injector Offset Select from Vacuum to MAP?

[Cringer]

...
But, by all means check the log out and tell me what your thoughts are.
...
Is it possible to add some fuel in at idle only without the wideband so this thing is not running so lean?
...
Attachment 141604

Sorry disregard my last message about invalid file. I was clicking the wrong link.

I would say your idle appears to be pretty stable. At this point your fuel trims reflecting the MAF and VVE being out of tune. You cannot just add fuel in closed loop. Rather you change the airflow model. More air = more fuel. But even so, the ECM is adding the proper amount of fuel in closed loop, so you are not actually lean.

Additionally, the O2 sensor voltage fluctuations (or lack there of) reflect Proportional and Integral tuning that needs to be done after a cam is installed. Yes I did a youtube video on that too. But there is no tool.

[Allen Vos]

The EOIT Assistant won't give you answers or suggest what you should do. It just makes visualizing and understanding the EOIT tune with relation to cam events easier. You are the tuner and need to know how to do it. This is why I made the first EOIT video as it goes into the theory.

I am not able to open that log attachment, it says invalid file.

But as of now I cannot use the subjective feedback that "fuel trims are higher" because you also stated "I have not tuned MAF or VVE". I would also suggest disabling LTFT, at least for doing this detailed tuning, if not permanently. Additionally, to cut through the EOIT vs fuel trim issue, you really need to look at the injector pulse width. And even then, the reported IPW does not include the modifiers related to short pulse adder, IPW vs Voltage, etc. So you can really look at the raw number.

My suggestion is to use the initial settings I sent. Then do your due diligence on tuning MAF and VVE and idle to get it dialed in as close as you can. THEN start messing with EOIT and see how that changes the fuel trims. As a sanity check you can even use the stock settings.

Question: is there a reason you changed [ECM] 275 - Injector Offset Select from Vacuum to MAP?

My apologies, I am not sure what happened with the log but I edited the post and re uploaded it.

Please take a look at it when you get a minute and let me know what you think.

I hope I am not bothering you with a zillion questions. I have watched all your EOIT videos. Its just sometimes its hard to retain everything in memory from the videos, so I ask questions for clarification, just to make sure that I am in fact doing the correct thing and not doing something wrong. I know how easy it is to make a mistake and then have to start over.

I am definitely using the EOIT settings you gave me and will work on the MAF, VVE and the idle this weekend. I do have to tone down my minimum air flow a little bit as well at idle

I have not read up on tuning the VVE and MAF as much as I should have since I have been focusing on getting it running with a nice cold start and proper idle but I think what I will do is add 10% fuel to the MAF and VVE at idle only for now to richen up the idle a bit to see what it does. Once I get the wideband then I can dial things in a bit better.

I am not sure what happened to Injector offset select. I do not remember changing it but my original LS3 flash has it on vacuum so I should prolly change it back.

If you don't mind me asking what does the Map/vacuum option do? I'm curious.

I do have one question when I get into the EOIT settings. I know that when you are adjusting EOIT, you are looking for the richest possible A/F mixture at idle which would ensure all the fuel is staying in the cylinder and not short circuiting.

Is there a way to change this on the fly or does it have to be shut down and reflashed every time?

What is your preferred method to do this?

I remember years ago when I tuned my "MegaSquirt" stand alone system I could make the changes on the fly with the engine running. It was a very nice feature.

[Allen Vos]

Sorry disregard my last message about invalid file. I was clicking the wrong link.

I would say your idle appears to be pretty stable. At this point your fuel trims reflecting the MAF and VVE being out of tune. You cannot just add fuel in closed loop. Rather you change the airflow model. More air = more fuel. But even the, the ECM is adding the proper amount of fuel, in closed loop, so you are not actually lean.

Additionally, the O2 sensor voltage fluctuations (or lack there of) reflect Proportional and Integral tuning that needs to be done after a cam is installed. Yes I did a youtube video on that too. But there is no tool.

Oops my bad, I didn't see this message before I responded to the last thread lol

I am about to sit down and watch your O2 sensor video and try to make some sense out of that.

As far as my idle goes, again I changed nothing in the VVE or MAF. It bone stock for an LS3.

I'm still trying to wrap my head around this. I remember what you were saying about adding a more aggressive camshaft that the VE of the engine drops at idle compared to stock and needs more air thus needing more fuel so that's why I just assumed I am running lean.

Not to mention what the fuel trims were doing.

So just to give this thing a bit more fuel at idle , I would just start by adding 10% to the numbers in the VVE and MAF table at idle and then see what the fuel trims do?

I think I was around 2200 HZ at idle with the map.

One thing I took note on is when the car was warmed up on the factory cam it only needed 6 g/s of airflow through the MAF.

With this Camshaft its at about 9.5 g/s

[Allen Vos]

I used to do this a long time ago.. I stopped and can't really remember why.

I'd suggest you do this in strictly SD first. The MAF can cause the issue you are describing just as much as trying to run closed loop with a bigger cam. That cam should do OK in closed loop. Its on the edge of what works but it should be ok.

Cam reversion hits the MAF sensor pulling air in and out.. so like a double dip in airflow measurement. It's too noisey to use with a larger cam like this.

Honestly, the VVE doesn't look appropriate for the cam. Like you still have work to do on it.

Lastly, Rich cars stink sure.. but lean cars are the ones that really burn your eyes.

Thanks for your Response

So Im not sure if you caught this but I dont have a wideband yet and right now Im just focusing on the startup, idle, EOIT and O2 sensor functions.

Yes I know its a pain without the wideband but it can be done at idle.

I literally have not touched my VVE and MAF tables yet, and was just waiting till my wideband showed up.

However it seems I need to alter VVE and MAF tables to get this thing idling a bit nicer so I was thinking of just adding 10% and watch the fuel trims.

I really want to be able to use the MAF and VVE together. Everything I have read says its the best way to go and guys have got it working well with larger cams.

[LS ROB]

You can use the fuel trims to make fueling adjustments for low to mid load areas, so you don't have to wait on your wideband. A wideband is needed for WOT tuning though. I honestly feel that you need to give it what the trims say it needs. Worst case scenario, you can change it back to the way you have it now. If you have an idle log, post it up so you can get more help.

Oh, does the throttle seem to hang if you blip it?

[Alvin]

Thanks for your Response

I literally have not touched my VVE and MAF tables yet, and was just waiting till my wideband showed up.

I really want to be able to use the MAF and VVE together. Everything I have read says its the best way to go and guys have got it working well with larger cams.

EOIT is not going to make a huge difference. VVE tuning absolutely should come first.


You can believe me or not about going strictly SD. I do this 9-5 every day. I'm speaking from a lot of experience.

[Cringer]

EOIT is not going to make a huge difference. VVE tuning absolutely should come first.


You can believe me or not about going strictly SD. I do this 9-5 every day. I'm speaking from a lot of experience.

I respectfully disagree. EOIT should come first. There is no reason for it NOT to come first. Do you suggest dialing in your airflow model THEN dialing in the hardware (injector/cam timing) which will impact your VE shape only to have to change it again? I do not understand this way of thinking.

EOIT is not going to move mountains, however, it is an important and overlooked detail of a proper tune. It impacts MPG, emissions, carbon/soot on your tailpipes and bumper, the goo that builds in your intake manifold and throttle body, and can cause misfires. There is literally no reason not to take a few minutes to set this up at the beginning of working up a new tune.

[Allen Vos]

EOIT is not going to make a huge difference. VVE tuning absolutely should come first.


You can believe me or not about going strictly SD. I do this 9-5 every day. I'm speaking from a lot of experience.

I don't see any reason why you would not want to set up EOIT. Its all part of tuning and makes complete sense to do it.

As far as speed density goes, yeah that's great for a race car, but on a street car, sorry but I would prefer the MAF to be in control if its possible and from everything I have read, it is.

Speed density may be your go to and a lot of guys just go that way because its easier to tune, but not this guy. I want to learn how this is done in great detail and so far Cringer is the only one on here that goes through things in great detail like no one else does so I do feel he's got a pretty good handle on things.

Respectfully if, your going to give advice to help people out a thorough explanation would go along way.

[Alvin]

Ok Good luck with things!

[Allen Vos]

Sorry disregard my last message about invalid file. I was clicking the wrong link.

I would say your idle appears to be pretty stable. At this point your fuel trims reflecting the MAF and VVE being out of tune. You cannot just add fuel in closed loop. Rather you change the airflow model. More air = more fuel. But even so, the ECM is adding the proper amount of fuel in closed loop, so you are not actually lean.

Additionally, the O2 sensor voltage fluctuations (or lack there of) reflect Proportional and Integral tuning that needs to be done after a cam is installed. Yes I did a youtube video on that too. But there is no tool.

OK, so just an update here on how the tune is going. But first a big thanks to Cringer for all his help. It would have taken me so long to figure this out without it.

I'll post the tune so far with my last log for you guys to checkout. Any feedback would be greatly appreciated, positive or negative.

I feel fairly confident with how things are going but any correction would be great to keep me on the right path to do things correctly.

Here is what I have done and figured out so far.

1) EOIT/SOIT> Cringer has done the math for me and with my setup. So just to recap my EVC is 394^ with my cam and the SOIT was set to 385^ which sprayed the fuel 9^ prior to the EVC.
Now don't forget I was doing this without a wideband so I tried different settings and used the fuel trims to try and find the richest setting with the best idle. In the end I set the SOIT to 389^ and it really cleaned up the way the car runs at an idle. LTFT came down significantly from 24% to somewhere in the 5% area. The car idled so much better with way less smell despite being catless. So 4^ on SOIT might not sound like much but it made a big difference and I'm now a big believer on setting EOIT and SOIT. It also brought the O2's back in line and they are at least switching from rich to lean and not staying stuck lean and drowning this thing out with fuel in closed loop. I still need to study up on O2 sensor tuning and dial that in a bit better.

2) I also dialed in the VVE and MAF tables so it could at least have a stable idle. I used Cringers method of tuning both LTFT and STFT and found I had to add about 10% airflow to the MAF curve and as far as the VVE table goes it was terribly rich so I had to reduce the airflow as much as 30-40%. You can see on the logs now that VVE , MAF and Dynamic airflow are all fairly close.


I am extremely happy with this so far and glad I was able to get a steady/stable idle using both VVE and MAF values. I have some work to do on the idle tables when cold as I do get some RPM oscillation's during cold start up and almost a stall, but it smooths out almost perfectly once it is at operating temperature. I'm going to start another thread on the idle part of things to try and sort that out.

Again, for those of you who helped me, a big Thank you so far.

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