VEMS Community Forum
Technical => Fuel Injection => Topic started by: iwbs on December 27, 2015, 05:55:20 pm
-
Hi everybody, as its getting colder outside I am having some new difficulties starting my car. Maybe someone could take a look at my cold start settings. After cranking for about 10s engine is trying to come alive, but it dies almost instantly. No matter how many times in a row I try, nothing changes. As you can see from vemslog I tried different settings, but it all ended flooding the engine. Here is my latest vemslog and memberspage:
http://www.vems.hu/filethingie.php?action=list&subdir=iwbs/cold%20start%20problems
http://www.vems.hu/wiki/index.php?page=MembersPage%2FIwbs
-
Config?
-
Are you running petrol or E85? Closer to 0 degrees celsius, you need to add quite alot on the cold start to get it to fire when running E85, that part can be a real pain for us in the colder countrys.. :/
-
You could use many more cycles of afterstart (100/66 now, go for at least 400/400 to begin with).
You can lower your warmup enrichment, just watch lambda as it warms up. Disable EGO correction for this.
Not sure what injectors you got, you could try firing them "simultaneously" instead for a greater chance of fuel in the intake once the engine turns. This can make warm starts a bit fuzzy as injector opening times and the settings for injector characteristics can produce very little fuel. Change the setting and you will see.
You picked 55% crank VE pretty much out of your VE table @ 100 kPa. That is a good start, but you can experiment with a bit more as well.
-
Thanks for the tips! It's running on petrol and I'm using OEM 330cc injectors.
I forgot to upload config in a hurry, will do it later.
As I mentioned my first attempt ended flooding the engine therefore I tried cranking VE 45% and afterstart cycles 400, also decreased cranking enrichment a little bit. That's how I got it working somehow.
Had to increase warmup enrichment by the lambda readings.
-
Config is included in the vemslog file, so no need to upload.
You have waaay too much cranking enrichment for gasoline.
Try 200% at 0 C and 140% at 20 C.
While cranking cold and not having any idle IAC valve, I generally have good results keeping throttle closed and when I hear first stumble of the engine then give it some throttle to raise idle speed.
-
At the moment it`s 350% at 0 degrees and 150% at 40 degrees, engine starts after few seconds of cranking. Tomorrow I will try to decrease cranking enrichment and we`ll see how it goes.
Here`s the latest vemslog: http://www.vems.hu/filethingie.php?subdir=iwbs/latest%20vemslog
-
which coils are you using?
-
At the moment it`s 350% at 0 degrees and 150% at 40 degrees, engine starts after few seconds of cranking. Tomorrow I will try to decrease cranking enrichment and we`ll see how it goes.
Here`s the latest vemslog: http://www.vems.hu/filethingie.php?subdir=iwbs/latest%20vemslog
From bmw stock car, cranking enrichment. For vems you need to scale with warmup enrichment.
bmw
temp multy
-30 9.66
-20 7.5
-10 3.45
0 3.08
10 2.5
30 2.1
60 1.8
90 1.25
-
Hi guys!
I really need our help because my car won't start in outside. There is -10degrees outside temperature.
2.0L Saab engine, with 1000cc injectors and coil is Bosch 2x2.
Little bit of promissing but when engine goes to warmup enchricment about 0-1sec and then engine dies.
Here is print screen about my settings. Tried so much change the settings but nothing helps. Flooded my engine and tomorrow i am gonna buy some new spark plugs.
(http://i5.aijaa.com/b/00170/14064311.jpg)
-
What injectors(low z or high z)? What voltage do you have on cranking?
Cold start with values from nissan sr20det
https://www.youtube.com/watch?v=23q2jm2mnyE
-
What injectors(low z or high z)? What voltage do you have on cranking?
Cold start with values from nissan sr20det
https://www.youtube.com/watch?v=23q2jm2mnyE
High Z. Voltage is like 11V while cranking. When it was warmer like 20degrees car would start with those settings but still needed couple of times to start up.
-
What injectors(low z or high z)? What voltage do you have on cranking?
Cold start with values from nissan sr20det
https://www.youtube.com/watch?v=23q2jm2mnyE
High Z. Voltage is like 11V while cranking. When it was warmer like 20degrees car would start with those settings but still needed couple of times to start up.
Do you have log of cranking?
btw i thin you have to low enrichment. Try 500% at 0deg and 600% at -20deg. Also check crank VE, usually is 70-90.
-
What injectors(low z or high z)? What voltage do you have on cranking?
Cold start with values from nissan sr20det
https://www.youtube.com/watch?v=23q2jm2mnyE
High Z. Voltage is like 11V while cranking. When it was warmer like 20degrees car would start with those settings but still needed couple of times to start up.
Do you have log of cranking?
btw i thin you have to low enrichment. Try 500% at 0deg and 600% at -20deg. Also check crank VE, usually is 70-90.
Sorry i forget to get log. Tomorrow i will take log with new spark plugs.
Are u sure about that 500% that seems quite high? Because those injectors are quite big? Req_fuel is now fine with the map when engine makes idle its afr is like 14.0.
What about that crank advance? My stock advance is 12 while idling at 800rpm.
-
What injectors(low z or high z)? What voltage do you have on cranking?
Cold start with values from nissan sr20det
https://www.youtube.com/watch?v=23q2jm2mnyE
High Z. Voltage is like 11V while cranking. When it was warmer like 20degrees car would start with those settings but still needed couple of times to start up.
Do you have log of cranking?
btw i thin you have to low enrichment. Try 500% at 0deg and 600% at -20deg. Also check crank VE, usually is 70-90.
Sorry i forget to get log. Tomorrow i will take log with new spark plugs.
Are u sure about that 500% that seems quite high? Because those injectors are quite big? Req_fuel is now fine with the map when engine makes idle its afr is like 14.0.
What about that crank advance? My stock advance is 12 while idling at 800rpm.
Upload a config so i can take a look.
-
Here is my config. Hope you can download it! Also my tachometer wont work but i think the problems is my rpm meter in the car.
https://drive.google.com/open?id=0B0YoTFa0ERo5UTBPZm5YMVE2bmM (https://drive.google.com/open?id=0B0YoTFa0ERo5UTBPZm5YMVE2bmM)
-
Your config is very bad(ign table, fuel table, injector settings, lambda table, mat compensation, accel enrichment...).
But i fixed cold start. Give me you email.
-
Why so bad?!
matti.mustamaki(at)gmail.com
-
ve talbe- your engine increase VE with boost and rpm, that is very unlikely
ign table- same advance at 3500 and rev limit, also very unlikely
i sent you config to email, so you can try cold start.
-
Also, your config is set to run in closed loop up to 7000 rpm, i would not recommend that.
-
At the moment it`s 350% at 0 degrees and 150% at 40 degrees, engine starts after few seconds of cranking. Tomorrow I will try to decrease cranking enrichment and we`ll see how it goes.
Here`s the latest vemslog: http://www.vems.hu/filethingie.php?subdir=iwbs/latest%20vemslog
From bmw stock car, cranking enrichment. For vems you need to scale with warmup enrichment.
bmw
temp multy
-30 9.66
-20 7.5
-10 3.45
0 3.08
10 2.5
30 2.1
60 1.8
90 1.25
So what you`re saying is that for VEMS, cranking enrichment needs to be scaled with warmup enrichment? For instance if I take multiplier 9,66 on -30 and my warmup enrichment multiplier on -30 is 1,3, then 9,66*1,3 gives me the actual cranking enrichment multiplier?
What about afterstart enrichment in this case? Is it also scaled with previous curves?
Btw I`m using Audi redtop coils.
-
Also, your config is set to run in closed loop up to 7000 rpm, i would not recommend that.
There is nothing wrong with that. If race cars who do 24hrs with the same lambda sensors can do it then why not VEMS?
-
Theres a video of a megasquirt seminar somewhere, some well known bloke, cant remember his name lol talking about wideband closed loop controlling individual cylinders on a land speed record car. By the sounds of it, they run EGOC all the way up to red line per cylinder
Here you go, found it. Slightly off topic i know.
http://youtu.be/ueqDFWti47g
-
Theres a video of a megasquirt seminar somewhere, some well known bloke, cant remember his name lol talking about wideband closed loop controlling individual cylinders on a land speed record car. By the sounds of it, they run EGOC all the way up to red line per cylinder
Here you go, found it. Slightly off topic i know.
http://youtu.be/ueqDFWti47g
I understood if that would be individual egt correction but wideband, that's expensive :D
-
The point is, these guys are willing to run egoc right up to red line on a very expensive engine, yet others say on here that its bad to run egoc past 4500rpm.
I think vems is better placed to be honest as if the sensor or circuit dies, vems ignores it and runs open loop. What happens with an ecu taking a 0-5v signal from a wideband controller when a sensor dies?
Max enleanment/enrichment % should be capped such that its not going to kill the engine if things get out of hand because of a dead sensor anyway, so running egoc all the way up to red line is neither here or there from a safety point of view. What if something changed suddenly for another reason that caused a sudden lean off, and egoc was not reacting to it because it was dissabled? Half a dozen of one and 6 of the other. Things have moved on, and egoc reacts faster than it use to, that and with these new LSU4.9 sensors, i dont see why not.