Help with Vems idle issue and cold start (logs)

[morris400]

So finished the build process on my k24 7400 and mechanically the car is 100% better then before ... but I am having issues with the idle and ISV.

The ISV has been bench tested and it does function and it functioned prior to this build. With the ISV plugged in to the car the idle will bounce around 700 to1200. With the ISV unplugged it idle steady at 1000 but if I give it gas it will rev normally but feel like it wants to stall when the rpm return to idle.

The TPS has been calibrated in vems tune with the TPS wizard and the manual way both returning the same values . 227 and 16.

In the morning on cold start or even an hour after turning it off it will not want to start. When I turn it over it does start and the rpm go to 11-1200 then drop and stall. It will do this a few times before it finally starts and idles...but only with the isv unplugged.

I'm kinda lost on this tuning thing as it is really new to me. I want to learn but also cant figure out why this is happening.

I've checked everything, there is no vac leaks, all vac lines are new silicone. Pcv system is stock but in great shape. All sensors and grounds are connected. ( minus the isv ) no cross connections...the aud coolant pump works...which it did not before this build lol.

I'm leaning towards the TB assembly in some way but really need someone with more knowledge and experience with vems to shove me in the right direction.

[morris400]

This is the ign map the tune is running. Now this worked on my buddy's car which was running all the hardware I have now. But it not running good on mine. Had a friend look at it and he said the timing between 700 and 1200 looks low. Should be 10.00 and 15.00 respectively. Do these numbers look a little off for my set up?

K24 7400
630cc
7a cams
2.0 coils
Stock bottom end
Rebuild head (stock)

[morris400]

I have managed to "kinda" sort out the idle. I adjusted the timing a little higher in the idle area and managed to maintain a steady 850 idle. However with the isv connected it will want to stall if I rev and let the rpm return to idle. If I run with the ISV unplugged it will idle correctly based on the ign based idle setting I have.

New issue is that at half throttle of little throttle... the car will jerk and buck. Under higher throttle it will be good. Any ideas what may be causing the jerking?

[ChrisAudi80]

What fuel are you running? E85?
I don't think it is your ISV, but your idle timing is very low. It doesn't surprise me it wants to stall.
Have a look through these link:
http://www.enginebuildermag.com/2012/01 ... ooth-idle/

Watch Andy Whittle's videos. They are mainly about Megasquirt, but apply to all SEM and are extremely educational.
He has some recent videos about idle control.
https://www.youtube.com/channel/UC6UMj0 ... N8S-aD6M-A

[ChrisAudi80]

Just looking through your config and have a few comments:

-Forget about your buddy's set up. This is yours and is not the same. How do you know his is 100%?

-I see that you have injector end angle set to 210 degrees flat everywhere. Why?
If you use injection end angle, it needs to change with RPM. Just set it to 720 at all RPM. It will run smoother and will be WAY easier to tune fuel.

-Set overrun fuel cut to 0 kpa, but keep the rpm settings. That might be why you have hiccups.

-Boost target reduction over 90C? You don't want full boost? 90C is normal running temp. Set that higher to say 105C.

-Conditions for enabling EGO control:
I recommend you set warmup time to at least 40seconds and minimum temp to 75C. You don't want EGO control to fight your warm up do you?

-VE table needs a lot of work. I guess you are tuning it still.

-Ign timing: Like I said, your timing is too low in idle area. In the cells 700-1200rpm and 30-60kpa, set to 16 degrees if you want to be safe.

-Lambda target table is a bit off. Try resetting lowest rpm from 1200 to 800. Then change target lambda to 0.95 in the 800 column between 30 up to 102kpa.
It will idle a little smoother.

Actually, I got sick of typing. I have made some changes to your config to reflect the recommendations. I have not touched any critical stuff, but please look through it so you can see.

Hope it helps.

[morris400]

Thank you Chris,

I'm still very new to the tuning side of the house and need to learn the values and how they work.

I know this tune was base off a a base tune from Marc and it worked on my buddy Shawn's S4 for him. I knew some things would have to be fine tuned for my car.

This was the push I need that kind of explains things to me better. I have a couple different config options right now, this on from you and 1 from Dace. I'll run them both separate and then see what I should adjust from there.

Thank you again and I will let you know what the results are.

[ChrisAudi80]

Thank you Chris,

I'm still very new to the tuning side of the house and need to learn the values and how they work.

I know this tune was base off a a base tune from Marc and it worked on my buddy Shawn's S4 for him. I knew some things would have to be fine tuned for my car.

This was the push I need that kind of explains things to me better. I have a couple different config options right now, this on from you and 1 from Dace. I'll run them both separate and then see what I should adjust from there.

Thank you again and I will let you know what the results are.

You are welcome. I am no expert by a long shot, but some of the settings you had will cause weird issues.
I see you have an old style 'n' ECU and you run FW1.2.11. I'm in the same boat.

Your acceleration enrichment looked off as well, but I didn't touch that. I'd recommend you set accel RPM enrichment to 100 flat. Get your VE table a little closer by first letting it warm up idling. Then go for an easy cruise. Actually, disable boost and get your 30-100kpa cells dialed in as close as you can.
Find a flat quiet road and get to 3rd and slowly accelerate from 1800 to say 4500. That should get you good data for cruising.

When it comes to your ISV issue, keep it disabled for now and get your idle area VE rock solid. Do you know how to turn off EGO correction?

[morris400]

I ran my recent log through tune by statistics and found out I'm in need of alot more fuel down low. I adjusted the VE table to get a really nice idle with ISV today. 850 steady. I also dropped the boost down and made a few WOT pulls. Still have some tinkering on the VE table but it's running and it steady. I think the dueling and timing were my biggest issues. 5he base tune i was using was tuned for sea level...I'm 2000ft + above.

I also had a boost leak that I managed to sort out yesterday.

[morris400]

The idle I can nail down now but if I'm stopping or letting the rpm return to idle I have to feather it down slowly to prevent stalling. If driving the car does pull hard and nice. It's just the return to idle right now. I think the car is running pretty rich right now but that safe for me. I lowered the boost to 20psi as well. I've attached my most recent log and config for review.

[morris400]

Thank you Chris,

I'm still very new to the tuning side of the house and need to learn the values and how they work.

I know this tune was base off a a base tune from Marc and it worked on my buddy Shawn's S4 for him. I knew some things would have to be fine tuned for my car.

This was the push I need that kind of explains things to me better. I have a couple different config options right now, this on from you and 1 from Dace. I'll run them both separate and then see what I should adjust from there.

Thank you again and I will let you know what the results are.

You are welcome. I am no expert by a long shot, but some of the settings you had will cause weird issues.
I see you have an old style 'n' ECU and you run FW1.2.11. I'm in the same boat.

Your acceleration enrichment looked off as well, but I didn't touch that. I'd recommend you set accel RPM enrichment to 100 flat. Get your VE table a little closer by first letting it warm up idling. Then go for an easy cruise. Actually, disable boost and get your 30-100kpa cells dialed in as close as you can.
Find a flat quiet road and get to 3rd and slowly accelerate from 1800 to say 4500. That should get you good data for cruising.

When it comes to your ISV issue, keep it disabled for now and get your idle area VE rock solid. Do you know how to turn off EGO correction?

Chris,

i have the EGO off and have been fiddling with the VE. i have increased the timing in the idle area to 15deg but i noticed on your config that you went to 21, could raising my ign timing to a bit higher help prevent the stalling?

[ChrisAudi80]

Thank you Chris,

I'm still very new to the tuning side of the house and need to learn the values and how they work.

I know this tune was base off a a base tune from Marc and it worked on my buddy Shawn's S4 for him. I knew some things would have to be fine tuned for my car.

This was the push I need that kind of explains things to me better. I have a couple different config options right now, this on from you and 1 from Dace. I'll run them both separate and then see what I should adjust from there.

Thank you again and I will let you know what the results are.

You are welcome. I am no expert by a long shot, but some of the settings you had will cause weird issues.
I see you have an old style 'n' ECU and you run FW1.2.11. I'm in the same boat.

Your acceleration enrichment looked off as well, but I didn't touch that. I'd recommend you set accel RPM enrichment to 100 flat. Get your VE table a little closer by first letting it warm up idling. Then go for an easy cruise. Actually, disable boost and get your 30-100kpa cells dialed in as close as you can.
Find a flat quiet road and get to 3rd and slowly accelerate from 1800 to say 4500. That should get you good data for cruising.

When it comes to your ISV issue, keep it disabled for now and get your idle area VE rock solid. Do you know how to turn off EGO correction?

Chris,

i have the EGO off and have been fiddling with the VE. i have increased the timing in the idle area to 15deg but i noticed on your config that you went to 21, could raising my ign timing to a bit higher help prevent the stalling?

It could help. However, you haven't said what fuel you use. Is it E85? That is important. If so, 21 is OK for above 1200.
I use 18-20 degrees in my idle area. Mine idles at 800 with AC and 1050 AC off. It does drop to 600 when dropping, but doesn't stall.

It could be you still have a vacuum leak. On the AAN, there is a shitty little T hose under the IM behind the TB. If that cracks, it idles crap.

I'll have a look at your new files tomorrow.

[morris400]

I'm using 91 oct. I went through and fixed any "would be vac leaks" found a couple that may have been a issue. I drove today and the car idles better and no longer stalls. I made changes to the IAC settings that helped. Problem areas I have now are starting...either cold or warm it will still struggle to fire up. Takes a few times. I'm thinking maybe the priming and cranking setting are off? I idle rich right now, .87 lambda. I'll be making corrections to the VE table to lean out the idle area to get closer to .98 lambda.

[IslandRinger]

I'm using 91 oct. I went through and fixed any "would be vac leaks" found a couple that may have been a issue. I drove today and the car idles better and no longer stalls. I made changes to the IAC settings that helped. Problem areas I have now are starting...either cold or warm it will still struggle to fire up. Takes a few times. I'm thinking maybe the priming and cranking setting are off? I idle rich right now, .87 lambda. I'll be making corrections to the VE table to lean out the idle area to get closer to .98 lambda.

Keep in mind Kenny, Canadian fuel Octane ratings are not quite equivalent to their US counterparts. It's been proven many times by various tuners. For example, people that have tuned on Shell 91 from the US have varied results when running the "same" Canadian Shell 91 including pinging. Just thought it would be a useful bit of information as many of the folks here are offering tuning advice from the US and other parts of the world. I know of a few local guys to me that have gotten tunes across the border that just wouldn't behave the same once they filled up back home. Some of them have solved the issue by running meth-injection which helps with the pinging. Others have had to adjust the tunes locally to work with our fuel.

Food for thought!

[ChrisAudi80]

I'm using 91 oct. I went through and fixed any "would be vac leaks" found a couple that may have been a issue. I drove today and the car idles better and no longer stalls. I made changes to the IAC settings that helped. Problem areas I have now are starting...either cold or warm it will still struggle to fire up. Takes a few times. I'm thinking maybe the priming and cranking setting are off? I idle rich right now, .87 lambda. I'll be making corrections to the VE table to lean out the idle area to get closer to .98 lambda.

So, pump gas. In that case I have no experience. That said, I remember seeing 45 degrees advance in your ignition table. That is too high for 91 IMO. Drop that down to 35 max just to be safe. Do you have knock sensing on? You need that.

0.87 idle when cold is OK. Not warm.

Haven't looked at your new files yet. Hang on.
Just notice your cranking VE is 40. Change that to 75. See what happens.

[ChrisAudi80]

Dude, please don't floor it with this tune. You will blow your shit up.
1.1 lambda at 184kpa? 0.99 at 233kpa? No. Just no.

Why is your coolant only 85C? What thermostat do you use? It should be at 90C.

You really need to get your vacuum area tuned first. Then boost. So, as much as you can below 100kpa. Your tables need rescaling.

[ChrisAudi80]

Please update the attached config into the ECU. You know how to do that, right?

I have made a bunch of changes. Especially in your VE, ignition and lambda tables. I have also turned down the boost a little.
This engine is not ready for 230kpa.

I beg you to go for an easy drive. Like I said before, let it idle until warm, THEN go for a drive.
Just take it easy through the gears. Try to accelerate slowly 1500-4000 first while logging. Do that in second and third.
The go home and look at the log. I don't know how you have your log view set up, but you need to watch target lambda and lambda, VE and corr VE.
Those number need to match.
Tuning out of boost MUST be done first.

Otherwise, I can look at your new log and make changes. WARNING: I am not responsible for your engine.

[morris400]

I agree with what your saying. I had turned the boost down already from 298kpa ro 230kpa. I will go lowered as per your config. I have been using the lambda screen, VE screen and the timing screen when viewing logs. I watch this last log a few times and at 230kpa MAP I was around .87 lambda idle was .87 lambda. There is a really weird spot between 4500 and5k that went lean. I say that for sure just have not made the changes yet.

My T stat is the stock T stat and it's new. At idle I'll see higher coolant temp around 90-91..driving I see 85-87. It's always been like that for me...remember I'm in Canada @ 2000ft above sea level and on the day I mad this log...0degc.

I will make the changes as you have mentioned. I have ran this tune thru tune by statistics and there are a few recommended changes on the VE table as you have said. I need to lean out idle a bit to achieve the .98 lambda

[ChrisAudi80]

I agree with what your saying. I had turned the boost down already from 298kpa ro 230kpa. I will go lowered as per your config. I have been using the lambda screen, VE screen and the timing screen when viewing logs. I watch this last log a few times and at 230kpa MAP I was around .87 lambda idle was .87 lambda. There is a really weird spot between 4500 and5k that went lean. I say that for sure just have not made the changes yet.

My T stat is the stock T stat and it's new. At idle I'll see higher coolant temp around 90-91..driving I see 85-87. It's always been like that for me...remember I'm in Canada @ 2000ft above sea level and on the day I mad this log...0degc.

I will make the changes as you have mentioned. I have ran this tune thru tune by statistics and there are a few recommended changes on the VE table as you have said. I need to lean out idle a bit to achieve the .98 lambda

Your weird idle and 4.5k-5k is probably because of the 210 degree end angle injection. I changed that to 720. It's not ideal, but best for now to get the VE table in line.
You were not at 0.87 at 230, except briefly. It leaned out severely after that.
See picture for an example logview.

[ChrisAudi80]

Please see picture.

The large red circle shows the lean area. You hit 1.00 @ 233kpa. Not good.
The yellow box shows target lambda and actual lambda. Those need to match as closely as possible.
The light blue boxes compares current VE and VE correction recommended. Those need to match too in order to get what you need.
You had no EGO control above 90% TPS IIRC, so it was not adding fuel.

Tune by statistics is not a good way to tune. This is because I don't know your filter settings and it usually disregards MAT. This has an influence.
Go cell by cell. You can try to free rev it sitting still. Slowly climb in revs. Adjust the VE table accordingly. It won't be completely correct when driving and only a certain kpa line, but better than nothing.

[morris400]

i watched the log in that area, there is a section of my VE that need adjustment and its clear as day, 4500 to 5k at 230kps is lean. but from 3k to 4500 is bang on .85 and from 5k to7k its .85 i will make small adjustments and blend the VE table in those blocks. if you watch the log in the lambda screen with the VE open you can see when it leans out and its suoer clear. watch from 10:20 to 11:00 on the log.

[ChrisAudi80]

You are getting the idea. However, as you might know, you need to avoid sharp dips and peaks.

If you are on say the 200kpa row and yo have a good value at say 4000, the VE value after 4000 needs to be same or higher.
It's called interpolation.

Can you post up a new log?

[morris400]

that is the changes I made. I will post a new log when I can get the car out again. should be tomorrow.

[morris400]

Chris,

attached is a long from friday while driving home. seems i still need to add fuel

[ChrisAudi80]

Chris,

attached is a long from friday while driving home. seems i still need to add fuel

I'll have a look.

[ChrisAudi80]

Chris,

attached is a long from friday while driving home. seems i still need to add fuel

Morris, based on what you sent, it seems like you are not uploading the config I attached before. What I would like you to do is this:

Insert USB to your laptop.
Turn key to on position. Do not start yet.
Start up VEMS tune.
When VEMS is online (you see the gauges), press file, then open config file, then select the config I made (morris400 REV2), when it ask to upload complete file press OK two times.
After that, the config I sent is in the ECU.
Now, you start the car.
This is the log I need to see. Every time you log and there is a change, you need to follow the steps above. Otherwise it does not implement the changes.

I still see the old config you had. That means it still uses the old values.
For example, the conditions for EGO enabling have not changed. Same with injector angle injection is still at 210 (should be 720 for now).
However, you turned off EGO correction somehow. We need this on. That is why you have lean conditions.
You only turn off EGO correction when your VE table gets close for fine tuning. The way you turn off EGO correction normally is to set step size to 0.
Just set rich and lean limit back to 15% for now.

Please start the log before you start the car. That way the warm up will be logged. Leave it idling until coolant is warm. For you this seems to be 85C. We won't be able to see what lambda does before the wideband turns on before 40 seconds, but it can be interpolated. You need to let the wideband sensor warm up first.
Drive like a granny. Slow acceleration through the rev range. We are trying to get as much under 100kpa dialed in as possible.

Since you are in a cold climate, the benchmark for your MAT/TPS table will be 20C (100%). That is the area where the base VE tuning is done. Usually, it needs more fuel under 20C and less above. That table will be tuned later. Don't worry about that for now.

It looks like your idle is steady now. Keep in mind that the DEKA 630s are not really linear under 1.7ms of pulsewidth. That means that anything less than that the injector is unpredictable. So, it needs to stay above 1.7ms. Because you are on pump gas, it might need to run slightly rich. Say 0.95lambda. However, it looks like you are just on the limit.

Let me know if the above is not clear.