Help with Vems idle issue and cold start (logs)

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Re: Help with Vems idle issue and cold start (logs)

Postby ChrisAudi80 » Sun Nov 11, 2018 11:28 pm

morris400 wrote:
ChrisAudi80 wrote:Try this.


Will give this a shot for sure! You set the crank pulse to 0.0, why was that?


It's what I use. Also changed the number of cycles for afterstart.

You had 8.0ms of primepulse and no downscaling for temp. That means you were probably flooding the engine, hot or cold start.
You always inject 8.0ms in addition to cranking, afterstart and warm up enrichment. Way too much.
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Re: Help with Vems idle issue and cold start (logs)

Postby morris400 » Tue Dec 11, 2018 8:07 pm

gave the new file a go, and same issues. 3 starts and only the 3rd one mainatined idle. Thinking maybe the afters start enrichment? had the car out for a nice long drive, about 30 mins and another 10 mins of messing with the idle. ive attached my current config, my log file fromm today is to big . my main concern is no matter what RPM, when i stomp on the gas, it will lean out for a split second then lambda goes normal. is this normal?

the one thing i want to do is brake boost to hold a certin RPM while boost builds, weather is the trick right now. its pretty cold and i only have summer tires. im going to try some some more tuning this week.

thanks guys.
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Re: Help with Vems idle issue and cold start (logs)

Postby morris400 » Wed Dec 12, 2018 5:01 pm

Looking to see if I can get pointed in the right direction with the afterstart and warmup enrichments. The cranking indictment seems good cause it fires up fine, it just dies after 2-4 seconds. And during the warmup..if I blip the throttle with out allowing it to idle for a few mins first causing the car to stall. Thinking more enrichment would help?
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Re: Help with Vems idle issue and cold start (logs)

Postby ChrisAudi80 » Sun Dec 16, 2018 8:27 pm

morris400 wrote:gave the new file a go, and same issues. 3 starts and only the 3rd one mainatined idle. Thinking maybe the afters start enrichment? had the car out for a nice long drive, about 30 mins and another 10 mins of messing with the idle. ive attached my current config, my log file fromm today is to big . my main concern is no matter what RPM, when i stomp on the gas, it will lean out for a split second then lambda goes normal. is this normal?

the one thing i want to do is brake boost to hold a certin RPM while boost builds, weather is the trick right now. its pretty cold and i only have summer tires. im going to try some some more tuning this week.

thanks guys.


That lean peak is partially Accell Enr and incorrect injector ramp up. Looked through your config and noticed you changed strategy to simplified.
I changed that back to traditional with my injector settings, which work well for me. You changed afterstart cycles to only 16. That might be why it does not maintain idle. The stall on throttle off, might be not enough timing below the idle RPM. I have added 3 degrees to "catch" it at 700.

If you could make a log of about 10-15 minutes it would help. Letting it idle to get to about 50C coolant and then drive. An easy drive. No flooring!
In order to tune AE, you need to just press the throttle and hold it for 5 secs or more. That way the fuel stabilizes. Not on/off. Try small to medium throttle changes at idle, 2000, 3500rpm.

I have made some edits. You said my AE settings before did not work. Was it too rich or lean? Anyway, try this again.
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Re: Help with Vems idle issue and cold start (logs)

Postby morris400 » Mon Dec 17, 2018 4:12 pm

Hey Chris, hope thge holidays are treating you well.

i laugh at your post only cause you keep saying no flooring! lol. i agree, the only reason i do is to see if i keep getting that spike. for every drive i do, im crusing around at 60km/h with a merge on and off the hwy. i will say im overall happy with the VE table while crusing. maintains the requested lambda non stop. thats with ego off as well. during the warm up its rich, but after that its .95-1.0.

today i changed my crank EN and afterstart EN, was able to get the car to start on the second start super easy. so i do think im heading in the right direction there.

i will add more afterstart cycles, totally makes sence that it should help.

id say right now my only issue is that lean peak, and its only on quick accelertion. if i slowly increase boost it will peak at the req boost (no over boost ) and it wont spkie lean. its only when i mash the pedal that it spikes the comes back down to normal with in .2 of a second. ill use your Accel EN settings to try and correct this. would the billet comp wheel be the issue here? maybe it just spikes too quick?

i raised the EGO temp to 70 like you said, i ran into some issues with this today at idle after my run. EGO would come on and off at idle causing really rich idle. it would go from .81 to 1.0 at idle with the RPM at 900-970.

FYI, what i do is take your suggestions and plug them into my config file and rename it 15.1 or 15.2 ect for my
own record keeping. i make 1 or 2 changes per time so i know whqt the changes effect rather thenh making a bunch of changes all at once.
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Log from 15.4.vemslog
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Re: Help with Vems idle issue and cold start (logs)

Postby ChrisAudi80 » Tue Dec 18, 2018 1:03 am

morris400 wrote:Hey Chris, hope thge holidays are treating you well.

i laugh at your post only cause you keep saying no flooring! lol. i agree, the only reason i do is to see if i keep getting that spike. for every drive i do, im crusing around at 60km/h with a merge on and off the hwy. i will say im overall happy with the VE table while crusing. maintains the requested lambda non stop. thats with ego off as well. during the warm up its rich, but after that its .95-1.0.

today i changed my crank EN and afterstart EN, was able to get the car to start on the second start super easy. so i do think im heading in the right direction there.

i will add more afterstart cycles, totally makes sence that it should help.

id say right now my only issue is that lean peak, and its only on quick accelertion. if i slowly increase boost it will peak at the req boost (no over boost ) and it wont spkie lean. its only when i mash the pedal that it spikes the comes back down to normal with in .2 of a second. ill use your Accel EN settings to try and correct this. would the billet comp wheel be the issue here? maybe it just spikes too quick?

i raised the EGO temp to 70 like you said, i ran into some issues with this today at idle after my run. EGO would come on and off at idle causing really rich idle. it would go from .81 to 1.0 at idle with the RPM at 900-970.

FYI, what i do is take your suggestions and plug them into my config file and rename it 15.1 or 15.2 ect for my
own record keeping. i make 1 or 2 changes per time so i know whqt the changes effect rather thenh making a bunch of changes all at once.


That lean peak has nothing to do with your compressor wheel. It is just injector and AE settings. Your AE settings don't go high enough. Highest dTPS you have is 26, while when you mash it, it shows 66! That is why you go crazy lean! See pictures.
Another reason you have lean peaks on accel is because EGO is pulling a lot of fuel. It is canceled on throttle input, but it does have an effect.

I hate to say this, but your VE table needs a lot of work. You say it maintains target lambda with EGO on or off. Why does the log then show EGO correction 85%? I can see in the log with my settings that it pulls fuel almost everywhere. EGO correction should be 100% if on target. Another thing is that you reach very low IPW. Just 1.4-1.5ms. The Dekas are not really linear that low. They start to go unstable at 1.7ms I have noticed. That is why you have that weird oscillation in lambda and MAP between time mark 11.30 and 12.20, I think.

Is your thermostat new? Coolant never goes above 87C. I recommend you get a stock 87C 'stat.
I see the on/off EGO issue at the end. That is odd, but not because of the higher enable temp. That is something else.
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Kenny log pic 2 EGO corr.jpg
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Kenny log pic 1.jpg
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Re: Help with Vems idle issue and cold start (logs)

Postby ChrisAudi80 » Tue Dec 18, 2018 8:14 am

Something else.

I think it would be better if you rescale the VE table RPM at least. You have no resolution at cruise RPM.
Try scaling from 700 to 7000 for now and 30kpa to 260kpa. Same with the timing table. That way you get a better idea of what is happening.
If you have a row for every 10kpa upto 102, then in steps of 20kpa, it would be very useful.

You also need more AE. For sure. You WILL melt a piston if you keep going like this. The lean condition is quite long actually.

You are too rich in vacuum and too lean in boost. See attached config to get an idea of what I mean. You don't have to use it, but I do recommend it.
Understand you only want to change few things at a time, but these are quite essential changes. You are on pump gas, not E85.
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Re: Help with Vems idle issue and cold start (logs)

Postby morris400 » Tue Dec 18, 2018 10:01 am

Hey Chris,

I agree on everything you mentioned above. I was unsure how bad the lean condition was as it seemed really quick to me. As you can see in the log it's a split second, but obviously it's not good.

I'll load that 15.4 config as per the changes you made. The VE table looks really rich up high but I have less experience here so I trust you.

I have since added Acell EN on another config but not ran it yet. Pretty much everything you mentioned yesterday was after that log I posted. I made the cahanges but not tested. Like i said, I'd like to test this VE table so i will load your config as per.

I'll report back later with a log and my results.
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Re: Help with Vems idle issue and cold start (logs)

Postby ChrisAudi80 » Tue Dec 18, 2018 11:13 am

Sounds like a plan. Go easy at first.

Try to cover as much of the vacuum area as possible. Like slowly climbing in the revs in second gear and third. If you can cover the same rev range with two different MAP rows, it can really help predict the upper table. After that, low boost along the MAP rows. Then we have the third and fourth points. The table is not completely linear, of course. There is a changeover where it curves sharply in low vacuum. Say below 40 or so. Small dip around idle, but not too steep. What you might find is a very slight dip in the mid range. I've seen this in a few maps besides mine.

Speaking of steep, your ignition timing changes were very sudden. 10 degrees in 500 rpm. Should not really be more than 5. The table is more conservative now, but not badly. Pump gas, remember.

If it goes too rich in boost, it is not as bad as very lean. 1.2 @ 245kpa is not good.

I'm temped to give you my VE map and see what happens...

Also, a fuel pressure sensor would be good idea at this point. It has helped me understand better what's happening. If you see some weird shit happening like oscillations or sudden drops, you can save the engine too.
A decent 100psi sensor is like $150. Make sure it comes with a calibration cert. Wire it in to one of the open analog in channels. You will have to check how to do that on your PnP. There is a tutorial on the VEMS YT channel on how to configure that.
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Re: Help with Vems idle issue and cold start (logs)

Postby morris400 » Tue Dec 18, 2018 12:06 pm

for the thermostat, yes its new. the 87c is normal for my car, also remember were dealing with temps here right now of -10c as well. in the dead of summer here id expect to see that number higher for sure. but its brand new and its correct as the one i pulled out was not correct lol.

with the EGO correct not matching the current VE... what could be this cause? i see its off by about 10%. where should i look to solve this issue?

with the EGO on/off issue, it only started when i raised the temp from 26c to 60c. ill review other logs as well to see if the issue was there... but this was the first time i recall this issue
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Re: Help with Vems idle issue and cold start (logs)

Postby morris400 » Tue Dec 18, 2018 7:57 pm

Quick update. So I ran my file # 16 in which I only changed crank en, afterstart en, and accel en. And bam...fire up on 1st start. Let it idle warm and played around a bit with the idle VE znd it seems that lower the VE to 54/49 works perfect.

With the acceleration set the way you had it at 100% for the RPM enrich did not work at idle. Every time I did a quick blip the rpm would drop to 500 and go super rich (.70) then come back. So I dropped the accel en at 1000/3000 rpm from 100 to 30% and perfect. No bog and no stall.

I've not had a chance to drive it yet but will tomorrow morning and see it the accell en kills the lean spike. I have good feelings .

Chris, for your VE adjustment. I'm going to wait and see how the car drive before I use your VE table, I'm concerned it's really rich I'm watching my log now and what I'm seeing on between current VE and ego corrected VE is that my VE table is already really rich when crusing . 5-10% almost everywhere. When I hit boost it's when it goes stupid lean although the current VE reads 106% and corrected reads 144%.
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Re: Help with Vems idle issue and cold start (logs)

Postby ChrisAudi80 » Tue Dec 18, 2018 10:06 pm

morris400 wrote:Quick update. So I ran my file # 16 in which I only changed crank en, afterstart en, and accel en. And bam...fire up on 1st start. Let it idle warm and played around a bit with the idle VE znd it seems that lower the VE to 54/49 works perfect.

With the acceleration set the way you had it at 100% for the RPM enrich did not work at idle. Every time I did a quick blip the rpm would drop to 500 and go super rich (.70) then come back. So I dropped the accel en at 1000/3000 rpm from 100 to 30% and perfect. No bog and no stall.

I've not had a chance to drive it yet but will tomorrow morning and see it the accell en kills the lean spike. I have good feelings .

Chris, for your VE adjustment. I'm going to wait and see how the car drive before I use your VE table, I'm concerned it's really rich I'm watching my log now and what I'm seeing on between current VE and ego corrected VE is that my VE table is already really rich when crusing . 5-10% almost everywhere. When I hit boost it's when it goes stupid lean although the current VE reads 106% and corrected reads 144%.


Well, that is it! Current VE is what you have in the table, but the ECU says you need 144 in order to hit the requested lambda target. If corrected VE asks for 144, put that in. Then try again. EGO control tells you what you should aim for. It's not always spot on, but you get close.

The idea is to hold in certain cells so that fuel requirement stabilizes. Any sharp transitions cannot give good information for tuning.

That is why dyno-tuning is so much faster. You can hold the engine in the cells you want. It brakes down the car by applying load so opening the throttle further to go up the MAP axis at one RPM column. You do something like this with brake boosting. I cannot do that here because of traffic.
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Re: Help with Vems idle issue and cold start (logs)

Postby morris400 » Wed Dec 19, 2018 1:41 am

That 144% is only during the 1/2 second spike. After that the car at 220kpa pulling hard, the current VE is at 99 and corrected VE is 99. So I think if i make 230kpa 144% its going to bog really hard up high.

Something is up with the acceleration en. After tomorrow when I test the acceleration en changes I made I'll post results. After playing with the AE today at idle I do feel adding more AE in the higher rpm will help me alot and get rid of that spike.

I'm pretty happy today with the start up on the first key turn. That has been a burden for awhile. Read up alot today on acceleration en and it does appear that lean spikes are due to not enough en under quick throttle. Trying to keep the changes to 1 or 2 at a time so I can actually see and understand how each change effects the car.

Your idle changes helped alot, leaning out the idle just a bit, I was able to hit 1.0 lambda and stay at 900 rpm nicely.
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Re: Help with Vems idle issue and cold start (logs)

Postby ChrisAudi80 » Wed Dec 19, 2018 2:08 am

morris400 wrote:That 144% is only during the 1/2 second spike. After that the car at 220kpa pulling hard, the current VE is at 99 and corrected VE is 99. So I think if i make 230kpa 144% its going to bog really hard up high.

Something is up with the acceleration en. After tomorrow when I test the acceleration en changes I made I'll post results. After playing with the AE today at idle I do feel adding more AE in the higher rpm will help me alot and get rid of that spike.

I'm pretty happy today with the start up on the first key turn. That has been a burden for awhile. Read up alot today on acceleration en and it does appear that lean spikes are due to not enough en under quick throttle. Trying to keep the changes to 1 or 2 at a time so I can actually see and understand how each change effects the car.

Your idle changes helped alot, leaning out the idle just a bit, I was able to hit 1.0 lambda and stay at 900 rpm nicely.


Good to see it starts right up and the idle is better. The boost VE increase is probably because of lack of AE.
Your dTPS table only went to 26. This means if you have dTPS of say 50, it uses the value for 26, so not enough.

I have noticed my engine likes to idle at 0.95. More stable. Good to see yours is getting better. A good way to tune your idle area is to sit in the lowest load area and tune that, then increase load by turning on AC and lights. You can increase load slightly by pulling a little on the steering wheel so the PS adds load.
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Re: Help with Vems idle issue and cold start (logs)

Postby ChrisAudi80 » Wed Dec 19, 2018 6:00 am

Check out this video. Andy Whittle really knows his stuff.

https://www.youtube.com/watch?v=eF_uAxpbzCw

He has several very useful vids. Some are quite advanced, but this one should give you something to chew on.
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Re: Help with Vems idle issue and cold start (logs)

Postby morris400 » Wed Dec 19, 2018 1:36 pm

So today i got the car out and with the new settings for AE the lean spikes are all gone. i turned the boost down to 180 kpa ( 13 psi or so) and was more confortable with WOT pulls. car does not feel fast at 180 kpa but, under quick aceleration the car goes rich rather then lean now. still making some small adjustments to the AE but its night and day different now.

from watching the log ( i play the whole log and watch real time what the car is doing ) today and enjoying my coffee, i noticed the VE table is rich on the low end by 5 to 10% which for now im ok with. better rich then lean. Up higher the VE table is really good under boost VE matches corrected within 2% ans lambda is right on the Req with no lean spikes.

idle is ok, sometimes it steady other timnes it bounces a bit then goes steady and some times its bouncing between 1200 ans 1000 but im sure the N80 provision would help i just dont want to open up the ECU yet.

going to get the wife some Christmas gifts and will log on my way to the mall lol.

ill attach a log tonight, the one i have now is to long, so ill make a shorter one and post that.
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Re: Help with Vems idle issue and cold start (logs)

Postby morris400 » Thu Dec 20, 2018 12:58 am

here is a run from today. as you can see the AE kicks in alot as i start to push the throttle, as it gets to 100% AE is gone and when i over boost to 205kpa i run lean for a split sec. thoughts?

I did 3 pulls and all were the same issues. This lean issue is my main concern right now so I'm trying to nail this down. Really need some help on the AE side of the house.

I've since adjusted the dTPS/map in a hope that it helps. Chris you said the if the dtps reads higher then the scale, say 50 and I only have valve for 26 it will use that 26 value... my issue is that my 26 value was 198%...198% seems like alot to me. Either way, I checked my log and I dont see dtps anywhere near the lean spot not near 100% WOT . I guess I could say...I'm lost on this one.
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Re: Help with Vems idle issue and cold start (logs)

Postby ChrisAudi80 » Thu Dec 20, 2018 3:57 am

morris400 wrote:here is a run from today. as you can see the AE kicks in alot as i start to push the throttle, as it gets to 100% AE is gone and when i over boost to 205kpa i run lean for a split sec. thoughts?

I did 3 pulls and all were the same issues. This lean issue is my main concern right now so I'm trying to nail this down. Really need some help on the AE side of the house.

I've since adjusted the dTPS/map in a hope that it helps. Chris you said the if the dtps reads higher then the scale, say 50 and I only have valve for 26 it will use that 26 value... my issue is that my 26 value was 198%...198% seems like alot to me. Either way, I checked my log and I dont see dtps anywhere near the lean spot not near 100% WOT . I guess I could say...I'm lost on this one.


I understand tuning AE is frustrating. I struggled with it too for a while.
Kenny, I don't want to be a dick, but you really are not listening. Like I said many times, those kind of lean spikes are going to kill your nice rebuilt engine.

That 198% is the max. Cannot go higher. It is too much actually.
The reason for it not being enough is because of your AE RPM table. It is subtracting enrichment again because it is (way) below 100% which is the base line.

You said you are starting to figure out AE. Good.

I have made some changes to your target lambda table. Its nice to see it maintains target, but 0.88 at 200kpa is a a little lean still. I have changed that to 0.85.

Again, I have changed the AE tables. Have added some fadeout time because it seems it is not long enough.

You need to play with JUST dTPS. Only that. You said my settings made it go very rich at idle when using AE. That is normal. It is partially because there is no load on the engine and also because you back off immediately. So, fuel is dumped. That is why stop and go uses so much fuel. There is also the issue of fuel film, but that is very advanced.

So, I put 1000rpm at 80%, the rest 100%. Cruise along at 2500, then press with a little change first, then move on to more throttle change. Hold the throttle after accel, do not back off for at least 5-6 seconds. If you see lambda dip to below target lambda then recovering to target, good. If lean spike, add more enrichment at that dTPS point. So, say dTPS of 20 and still lean, increase % AE. See pic.

The reason for the 100% in the RPM table is because some FW has 0% as base line, but not 1.2.11. There 100 is base. Most engines need more enrich at lower RPM, but less at higher. Because of the fast change in kpa, it needs extra fuel to cover the sudden change. Say you have dTPS 25 with 40% enrich at 2500, it will need less at say 4500. If dTPS 25 with 40% extra is good at 2500, it will be too much at 4500. That is what the RPM table is for.

I have attached pictures which attempt to explain it. There is a delay between dTPS and lean peak. That is what the fadeout is for.
Attachments
Kenny AE dTPS table.jpg
Kenny AE dTPS table.jpg (297.68 KiB) Viewed 4500 times
AE Kenny.jpg
AE Kenny.jpg (286.65 KiB) Viewed 4500 times
kenny #16 5ver2.vemscfg
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Re: Help with Vems idle issue and cold start (logs)

Postby ChrisAudi80 » Thu Dec 20, 2018 4:04 am

I would also recommend to turn off boost control for now to tune the VE table.
If you only run wastegate it does not spool so fast, so you can dial in VE first before AE. Slowly increase throttle until you go into boost with very slow increases.

As you might understand, an incorrect VE table will drive you up the wall with AE. The changover area around 102kpa is critical to get right. With full boost DC, it is hard to sit on 120 kpa, 140kpa, which are the cells you usually zoom past but do have a significant effect on transitions to 200kpa.
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Re: Help with Vems idle issue and cold start (logs)

Postby morris400 » Thu Dec 20, 2018 6:53 pm

your not being a dick, you care and for that i thank you! i lowered the boost to keep it from going crazy lean as the only way to see if the lean spikes are getting reduced is to mash it. trust me i dont like it which hints to why o only do 1 or 2 pulls every log ( 1 hour drive)

if i increase throttle slowly i dont over boost and dont run lean, its only when i go from 0-100 quick when i see the lean spike. i understand the fade out being longer could help this. looking at the log id require .75 fade out time. i feel if i was not overboosting id be ok, that was why i lowered the boost by 50kpa to see if it was over boost related or VE Table related, no matter what im overboosting by 20kpa and spiking on the over boost.

with setting the AE Rpm to 100 baseline ( good to know as i thought 0 was base) was where it ran really rich, so rich that at idle if i touch the throttle the rpm bogs down to 500 and almost stalls out. after dropping the 1000 and 3000 to 30% it was better. during higher RPM i had it set to 60% at 4000 and 6000 and i did not notice a lean spike ( this was with no dTPS change) ill use your rpm and dTPS settings and see.

ive attached a log from the 16.4 file which shows how the pull with old setting reacted. no spike under boost and no overboost but really rich
Attachments
Log of pull from 16.4.vemslog
(86 KiB) Downloaded 111 times
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Re: Help with Vems idle issue and cold start (logs)

Postby ChrisAudi80 » Fri Dec 21, 2018 2:44 am

morris400 wrote:your not being a dick, you care and for that i thank you! i lowered the boost to keep it from going crazy lean as the only way to see if the lean spikes are getting reduced is to mash it. trust me i dont like it which hints to why o only do 1 or 2 pulls every log ( 1 hour drive)

if i increase throttle slowly i dont over boost and dont run lean, its only when i go from 0-100 quick when i see the lean spike. i understand the fade out being longer could help this. looking at the log id require .75 fade out time. i feel if i was not overboosting id be ok, that was why i lowered the boost by 50kpa to see if it was over boost related or VE Table related, no matter what im overboosting by 20kpa and spiking on the over boost.

with setting the AE Rpm to 100 baseline ( good to know as i thought 0 was base) was where it ran really rich, so rich that at idle if i touch the throttle the rpm bogs down to 500 and almost stalls out. after dropping the 1000 and 3000 to 30% it was better. during higher RPM i had it set to 60% at 4000 and 6000 and i did not notice a lean spike ( this was with no dTPS change) ill use your rpm and dTPS settings and see.

ive attached a log from the 16.4 file which shows how the pull with old setting reacted. no spike under boost and no overboost but really rich


That log was perfect. What you see happening there is correct. What you call overboost is no issue. It is not causing the lean spike. AE is only for the initial jump from low kpa to high. I'm a little jelly that you can hold boost so steadily.

Almost stalling out is not completely because of very rich, that also has to do with timing. Remember I put in 3 degrees more at 700? That is to "catch" it and push it back to idle.

If you touch the throttle and it rich bogs, then you need to reduce AE % at that dTPS. Say dTPS of 4 or 5. As discussed already, if at higher rpm, like 2000 it is not enough, that is when you adjust the RPM scale like you are.

In the mean time, cruise around at very low RPM to tune your VE table. I mean 1000-2000rpm. Find a quiet road and just cruise along in 2nd gear between 1000-2000, then 3rd, then 4th. These gears will cover different MAP rows. Try to limit throttle movement as much as possible. Hold certain RPM or MAP points. Do this with EGO off. This way will dial in VE and daily driving will be much smoother. Same with above 2000.

If your VE table is off, it will mess up the AE.

You have an interesting event in your log from timemark 35.00 to 35.8. There you can see the effect of EGO control messing with your fueling. EGO correction is at 95%. Then, a small change in kpa makes it go a tad lean, 1.07, even though VE in that cell is nearly the same as requested. This why nailing the cells as accurately as possible is key. The same can occur everywhere.

Then, at tm 38.4 you can see why your low dTPS is too rich. Only 4 to 6, but lambda drops to 0.81 in the trough. So, reduce the AE %.
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Re: Help with Vems idle issue and cold start (logs)

Postby morris400 » Fri Dec 21, 2018 2:52 pm

Took a nice long hour drive today. Had to revert back to config 16.4 as the changes I made in 16.6 would not allow the car to start. So I went back to 16.4 which I knew worked. I
Changed the AE settings on both dtps and rpm. Then turned ego off and drive away. Everything felt pretty good. Was able to cruse around at 20kmh 40kmh 60kmh 100kmh and 120kmh for extended periods of time.

The only issue I could see was it's still rich so ill have to change the AE a bit but also...after coasting at 0% throttle for a few seconds, once I add throttle it stays very lean for almost a full second or longer before the lambda corrects.

Now with that I'm wondering if the fadeout time has something to do with that? I adjusted fade out from .48 to .75 as I needed more enrichment when I depress the throttle... it apears that by adding fadeout time I increased the lean period. Or am I reading this log wrong?

If crusing at lower throttle (15 or 20% say) if I press the gas to 80 or 90% i get no lean spot from what I can see...now I still get the rich dump before it comes back to normal. For this I'm confused if this Is dtps adjustment or rpm AE adjustment.

I ran tune by statistics today as well after my run. Pretty much said to drop the VE by 10% so I've done that and will log again on the same config with the VE changes.

Logs from this morning Attached.
Attachments
Log of pull dec 21 lean condition.vemslog
(32 KiB) Downloaded 100 times
log from Dec 21 AM.vemslog
(1.74 MiB) Downloaded 106 times
Last edited by morris400 on Fri Dec 21, 2018 4:13 pm, edited 1 time in total.
2016 VW Jetta 1.4T Daily Driver Stock.
1994 UrS4 - K24 7400 EFI Express tuned
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IF YOU CANT STAND BEHIND OUR TROOPS...FEEL FREE TO STAND IN FRONT OF THEM!
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Re: Help with Vems idle issue and cold start (logs)

Postby PRY4SNO » Fri Dec 21, 2018 3:16 pm

Hey Kenny, I'm available to cruise around during the day if you want some help with live tuning. Tough to drive in the winter and tune all by yourself, no? ;)
Find me on Instagram @pry4sno

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Re: Help with Vems idle issue and cold start (logs)

Postby morris400 » Fri Dec 21, 2018 8:53 pm

not sure what happen after i used TBS this afternoon but it felt like i went backwards. all i did was redo the VE as per TBS and the car ran like utter junk. would not idle to save its life and at some point VEMS decided to change my idle RPM to 0. i shut everything off and loaded up the config from this morning and same issues. idles like junk, now idles lean. i had an issue with warm/hot start, it just cranks and cranks, i habe to hold throtle at 100% to get it to fire up on warm start.

going to try again tomorrow but that was a fustrating afternoon on what i thought would have been a soild run.
2016 VW Jetta 1.4T Daily Driver Stock.
1994 UrS4 - K24 7400 EFI Express tuned
2001 B5 S4 Stg 3- ( gone! Dropped valve cyl 4)

IF YOU CANT STAND BEHIND OUR TROOPS...FEEL FREE TO STAND IN FRONT OF THEM!
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Re: Help with Vems idle issue and cold start (logs)

Postby ChrisAudi80 » Sat Dec 22, 2018 2:01 am

morris400 wrote:not sure what happen after i used TBS this afternoon but it felt like i went backwards. all i did was redo the VE as per TBS and the car ran like utter junk. would not idle to save its life and at some point VEMS decided to change my idle RPM to 0. i shut everything off and loaded up the config from this morning and same issues. idles like junk, now idles lean. i had an issue with warm/hot start, it just cranks and cranks, i habe to hold throtle at 100% to get it to fire up on warm start.

going to try again tomorrow but that was a fustrating afternoon on what i thought would have been a soild run.


Here is advice numero uno: Do NOT use TBS. It is garbage and will only do your head in. Log, tune, log, tune yourself.

I wish you had posted up the logs from your 20, 40 60, etc kmh drive.

In the attached config, I have rescaled your VE table (AGAIN!) to create more resolution. You really need more cells in the low/mid rpm and in the vacuum range. You cruise at around 50-75kpa. No cells there. I have tuned some of the cells based on the Dec21 AM file.

About the long lean condition after reapplying throttle. That is because of two things: Overrun fuel cut and fuel film effect.

What happens when your close the throttle on decel is the injectors are shut off. Then the fuel film in the intake runners and bowls around the valves are "sucked" dry. Normally, the fuel film is in equilibrium, but because there is no injection, it pulls the fuel off the walls. So by the time you re-apply throttle it needs to build up film again. The low IATs also have some effect on this. There is no need to worry about it, because you are not applying any real load, but if you let off and then re-apply to go in to boost...

You can do two things. Turn off overrun fuel cut or increase AE %. AE RPM has nothing to do with it except with the cases I told you about before.

Could you make a log of the config I made and run it in 2nd from 2000 to 5000? First in vacuum, then boost. Slow RPM increase. Also, a log of it idling warm with lights and fans on and off. Like 20 seconds.

The VE table really needs to be 99% before AE can be done.

Better yet, get your buddy Party in the Snow (hehe) to tune the cells while driving. Much faster and safer. He''ll tell you what to do.
Smoothness in driving is key here.

EDIT: I just noticed you have the injectors firing simultaneously while cranking!! NO! Individually. See file.
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kenny #17 Rescaled VE table.vemscfg
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