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Author Topic: Warm-up enrichment tuning  (Read 9882 times)
16g-95gsc
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« on: November 19, 2013, 06:49:09 AM »

I am having a bit of difficulty and wanted some clarification.  I have installed EV14's, while leaving the intake tract completely stock with the exception of a K&N panel air filter.  I have KRKTE and TVUB dialed in to the point where I see roughly a 1% or so of 0 when up to full operating temperature while cruising and idling.  However, I see enormous corrections when the vehicle is cold (-14% or more), and I can feel hesitation through the throttle pedal. 

Clearly it is time to adjust KFFWL_0_A and KFFWL_1_A.  However, I would like to ask some questions to help me understand what I am looking at.  My experience has typically been with 2-dimension warm-up enrichment tables where you have coolant temperature on the X-axis and then percentage values in the individual cells.  However, these two parameters are 3-dimensional tables with temperature on both axis.  Therefore, what is the Y-axis temperature with respect to?  Additionally, the values within the cells are less than 1, so I am confused as to what they represent.  Do you add 1 and multiply?  For example, if the cell reads 0.31 it would then be 1 + 0.31 or basically 31% enrichment.  Perhaps these are mS values that are added to injector pulsewidth? 

I don't want to blindly begin adjusting these values, but I can't seem to find the answers that I am looking for when digging through what documentation and archives that I have come across. 
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oldcarguy85
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« Reply #1 on: November 19, 2013, 07:26:35 AM »

i don't really know much about your question, but i did come across this thread/message that might be helpful: http://nefariousmotorsports.com/forum/index.php?topic=320.msg27838#msg27838
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NOTORIOUS VR
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« Reply #2 on: November 19, 2013, 10:39:56 AM »

I always have to question when people think it's necessary to make adjustment to "start up" or enrichment maps. 

IMO (any my own experience using 1000+cc injectors) there should be no need to change anything.  If everything is done correctly the car should work just as it did with stock injectors.
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rnagy86
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« Reply #3 on: November 19, 2013, 11:59:48 AM »

I always have to question when people think it's necessary to make adjustment to "start up" or enrichment maps. 

IMO (any my own experience using 1000+cc injectors) there should be no need to change anything.  If everything is done correctly the car should work just as it did with stock injectors.

So what would you suggest to do in case KRKTE TVUB FKKVS is dialed in and all the trims are within 0-0.5%? Still fiddle with TVUB? I am asking because i've went from 550 EV14s to 750cc ones and everything is spot on except that I have a good amount of misfires during warmup and that is also random, sometimes i have almost nothing sometimes it is utter shit.
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userpike
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« Reply #4 on: November 19, 2013, 12:53:45 PM »

My 1.8t suffers from a lean warm up cycle with the EV14 550's. I haven't played with the warm up enrichment maps yet though.

I did however just find the check valves for the EVAP system that come right off the intake were not sealing well. So I was getting the "check DV " boost leak DTC with VCDS while the car sat idling during EVAP diag. Being that the car is already warm I'll have to wait till tomorrow or much later in the day to observe how the engine reacts to having properly sealing check valves. So air is no longer being sucked from the intake mani to the TIP during idle and on boost its not leaking to the TIP anymore either. Obviously the fuel trims will be better but unsure about warm up.

I say rule number 1 when migrating to bigger injectors is to make sure you are vacuum and boost leak free before hand or you are wasting your time trying to tune for them. You'll get them close, then fix the leaks and have to do it all over again.. also set fkkvs to all 1s then figure out krkte and tvub then fix the lean/rich spots in AFR with the fkkvs map.
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rnagy86
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« Reply #5 on: November 19, 2013, 01:03:28 PM »

My 1.8t suffers from a lean warm up cycle with the EV14 550's. I haven't played with the warm up enrichment maps yet though.

I did however just find the check valves for the EVAP system that come right off the intake were not sealing well. So I was getting the "check DV " boost leak DTC with VCDS while the car sat idling during EVAP diag. Being that the car is already warm I'll have to wait till tomorrow or much later in the day to observe how the engine reacts to having properly sealing check valves. So air is no longer being sucked from the intake mani to the TIP during idle and on boost its not leaking to the TIP anymore either. Obviously the fuel trims will be better but unsure about warm up.

I say rule number 1 when migrating to bigger injectors is to make sure you are vacuum and boost leak free before hand or you are wasting your time trying to tune for them. You'll get them close, then fix the leaks and have to do it all over again.. also set fkkvs to all 1s then figure out krkte and tvub then fix the lean/rich spots in AFR with the fkkvs map.

Sure ... Vac/Boost leak test was the first thing I did before migrating to the 750cc EV14s.
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16g-95gsc
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« Reply #6 on: November 19, 2013, 07:09:29 PM »

I always have to question when people think it's necessary to make adjustment to "start up" or enrichment maps. 

IMO (any my own experience using 1000+cc injectors) there should be no need to change anything.  If everything is done correctly the car should work just as it did with stock injectors.

As much as I'd love to have your experience, what else would you attribute perfectly smooth operation when warm (+/-1% trims), and yet a whopping -14%+ when dead cold.  Boost leak test was done a while ago, that can be immediately ruled out (although I don't see how it relates).
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NOTORIOUS VR
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« Reply #7 on: November 20, 2013, 06:45:06 AM »

Strange, I will be changing the injectors on my 1.8T soon to 630cc EV14's (GT500) and will see if I have the same issues or not.  But with my ID1000's on my S4 there was no issue at all w/ cold start even in the middle of a Canadian winter Smiley
« Last Edit: November 20, 2013, 10:27:12 AM by NOTORIOUS VR » Logged

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16g-95gsc
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« Reply #8 on: November 20, 2013, 04:56:17 PM »

My issue isn't cold start.  The car cranks and starts right up.  The issue is with the warmup enrichment, which takes place while driving afterwards.  The issue disappears as the car warms up, and it can clearly be seen in the fuel trims and felt in the throttle pedal.
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userpike
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« Reply #9 on: November 21, 2013, 01:01:43 AM »

mine runs lean only during the SAI pump operation. (first 30 sec after start up) warm up is fine for me and also normal driving.


I want to add that I am in Florida so that may not count so much because it's always like 80F here. The engine warms up within maybe 5 mins or so. I do drive it imediately after start but I also have an aftermarket radiator that is all aluminum construction and slightly larger capacity. I still haven't fixed my boost leak issue but the car has more power now than before after I replaced the check valves for the EVAP.  ..Still have the EVAP leak also. trims are 7.9 and 14.3 ATM. after all that, and fueling is still very close. me7 is some cool stuff. Cool I'll fix it soon enough, just have to make time to.
« Last Edit: November 21, 2013, 01:48:58 AM by userpike » Logged
rnagy86
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« Reply #10 on: November 21, 2013, 01:31:09 AM »

Strange, I will be changing the injectors on my 1.8T soon to 630cc EV14's (GT500) and will see if I have the same issues or not.  But with my ID1000's on my S4 there was no issue at all w/ cold start even in the middle of a Canadian winter Smiley
You probably have cute tiny beavers working hard in your ID1000's to push the proper amount of fuel  Grin
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ddillenger
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« Reply #11 on: November 21, 2013, 01:42:41 AM »

Clearly it is time to adjust KFFWL_0_A and KFFWL_1_A.  However, I would like to ask some questions to help me understand what I am looking at.  My experience has typically been with 2-dimension warm-up enrichment tables where you have coolant temperature on the X-axis and then percentage values in the individual cells.  However, these two parameters are 3-dimensional tables with temperature on both axis.  Therefore, what is the Y-axis temperature with respect to? 

Axis are Y: engine temperature, and X: engine temperature when last started.
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16g-95gsc
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« Reply #12 on: November 21, 2013, 07:13:51 AM »

Hmm, so the X-axis is then only referred to once?  Therefore it would act similar to the 2-dimensional warm-up tables that I'm used to.  Effectively it would then become a 2-D table that is placed vertically instead of horizontal.

What are the actual units in the cells ddillenger?  Normally they are greater than 1, indicating a multiplier for fueling.  In this case they are smaller so I'm not sure exactly what they mean.
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