I forgot to add that I upped those values and havE a strong feeling that's what is working for me.

 

Alright, so my kpa/load table is 1:1 right now.. 21:21, 31:31, 41:41, etc, up to 350:350.

My AFR is good at idle (when warm), and cruise. My fuel trims are out but I'm pretty sure I need to fix that with the RPM VE table. I haven't done that yet.

Now, if I'm on the interstate, ~4k RPM, and give it ~25% throttle or so I build 5-15PSI and my AFR goes to roughly 10:1. It's just wicked rich.

I took a log, and my load (and kpa, since table is 1:1) is 200-220 or so.

Now I know in the speed density thread, they imply that you should adjust your AFR by modifying the kpa/load table.. but I don't see how that will do much for me.
Check out my global fuel map. (I've bumped up a little square there testing, and pulled the 9's into the 10's. that's about it)


if I change the 350:350 entry, all I'm going to do is push the load cell that I'm hitting at 4k left or right. I'd have to push it all the way from 210 down to 80ish before my AFR would change.

Sooo, anyway, after all that rambling.. If I understand correctly, it won't do me any good at all to change that kpa/load table. What I really need to do is just adjust my AFR table that I posted above, so that those cells that I'm hitting in part throttle are leaner. Seems like I should shove the 60-120 load columns to the right by 6 columns or so. Just seems like I'm too rich.

Sorry for making that so long. Hopefully you read through most of it. :P
What are your thoughts?

 

Thoughts are. Are you starting fresh with your SD rom or are you modifying non SD map?

You need to take care of your Map VE and RPM VE tables before worrying about adjusting fuel tables.

1:1 is default. You need to lower the numbers based on what kpa range you're landing in if you want to lean out your fuel or increase to add fuel.

You need to first dial in idle. Regardless of cold start issues once warmed up. Log o2sensor feed back and see what it looks like at idle. If negative that means the ecu is pulling fuel because too much is being dumped(almost certain this will be the case for you) If positive the ecu is having to compensate due to lack of fuel. Once you get your idle set, move on to cruise. And then WOT.

 

I'm using the speed density rom 94171715.

But I don't understand what modifying the map VE will do for me around 200 kpa/load.. it would take a huge amount of adjustment to change my AFR at all, based on the cells I'd be hitting in the AFR table. Right?

But yeah, I'm hoping to take care of my fuel trims this weekend.
my LTFT's are as follows:
low: -0.095
mid: -11.0
high +0.1

Seems like I just need to figure out what RPM range is "mid", and bump those all +10%. I've searched around and couldn't figure out what RPMs are associated with which long term fuel trims.

Thanks again, you're a huge huge help.

 

I'm using the same ROM as u.

Here's my Map VE: And my RPM VEThe way I got mine within a certain threshold was to add or subtract 5-10% of the value for MAP at a time given the kpa that i'm working with.

What i've found for tuning Speed Density :

*11.0 - 30.9 = when you doing low speed cruise and switching through gears...pretty much low vacuum readings.
*41.1 - 61.1 = cruise if you're running rich on the highway lower the values, if you're too lean increase the values on the right side. Always work in 5-10% increments.
*101.0 = transitioning from low load to mid load. Around spool areas...2500 - 3500rpm
*200.3 -350.2 will be your WOT. Adjust both in-sync.

If you log properly this will make sense and is not rocket science.

Finally the RPM VE is your fine tuning. One or 2 points on RPM VE makes a big difference on fuel, so approach with caution. Always approach tuning with caution. You blow it up, that's your bad

 

Mid = 41 - 61 kpa...you're not adding you're subtracting.

Mid: -10 means the ecu is taking out 10% fuel due to your cruise condition being overly rich. Your wideband may not reflect this but the ecu is.

Hopefully you're logging your trims properly.
LTF Low = Let your car idle for 16 mins and look at final value.
LTF Mid = Cruise for 16 mins straight and a steady speed of 60 -70mph without drastically increasing tps position. Same thing, look at final value.

LTF Hi = not really needed. That's WOT open loop. Your wideband tells you where you are .

 

hah, yeah, whoops. I meant -10%.. Sorry. I understand fuel trims very well from ecmlink. I'm still just familiarizing myself with all of this evo ECU stuff..

Your SD tables seem way different mine. I think I'll take 10% out of 41-61 and see what happens.

The SD RPM table will change AFR at all loads for a given RPM, right?

 

Your SD tables are off. You can't leave it 1:1 and call it a day. Tune it.

41-61kpa VE for you - 10% should put you right on the money for trims.

Yes regarding the RPM. Regardless of load the RPM VE increase or decrease will change all load from idle > cruise > WOT

 

I don't understand what I need to do to the kpa/load table other than get my fuel trims dialed in. If my fuel trims are zero, aren't I good?
My AFR's seem good other than when I'm boosting at part throttle. I don't understand how changing the 200-250 kpa/load values will change my AFR at all unless I push them way over to the left in that AFR table. That's all I'm really doing, right? Changing the load value that the ECU uses to look up in the tables.

 

The Map VE and RPM VE tables are for getting within a certain threshold and adjusting driveability. The map/ rpm tables are doing the work the maf sensor does with the aid of the intake temp sensor.

At a certain kpa + rpm + load + TPS + coolant temp + vehicle speed = percentage of fuel added or removed.

Example. 61kpa: 61 may be rich or lean. If at that point the car is rich you have to tell the ecu, at 61kpa instead of giving 30% fuel give me 20% (insert value of 54.9)

RPM VE is more like maf compensation has a global impact on fueling.

Hope that helps a little more figuring out speed density

 

WOW! Results!! I tossed this on this morning before starting the car.

I flipped the key over. It didn't fire up quite as quickly as before (hardly noticeable), but when it started up it went right to ~11:1, and then pretty quickly started leaning out and went to ~14.7:1, oscillating higher and lower like it should.
The car started and idled, didn't have to do anything else. It also drove much better as it was still warming up.

Simply awesome.

If it keeps starting up rich, I'll lower some of those numbers a bit. But I'm much happier.

Thank you!!!

 

I wired my GM IAT through the MAF harness and its located in the manifold, just wondering if anyone had the values I need to use in the rom to get the scaling correct as I've seen a few different values. I'm assuming I need to adjust the SD IAT ADC Scaling (Insert MAT Sensor Scaling) in the speed density programming section?

Also is there an easy way of testign to see if my read values are what the temperature actual is appart from taking the sensor out and putting it open air and measuring various air sources (ie hair dryer etc)?

Thanks
Andy

 

AWESOME! I had a feeling it was that!

I think it will start out rich with those settings. I would lower the 245's to 220's. That way the ecu is not fighting as much to get it to stoich.

You're welcome. At least if someone else has the issue we know what it is.

 

I should sum up all of the good info in this thread into the original post. I think that this thread has a ton of valuable information in it. I'll see if I can do that after work tonight.

 

Follow his instructions.
http://se30.dyndns.org:8080/EVO/8859...AT_patched.zip
http://se30.dyndns.org:8080/EVO/9653...AT_patched.zip
http://se30.dyndns.org:8080/EVO/9417...AT_patched.zip

https://www.evolutionm.net/forums/ec...e-logging.html

Insert the values from the patched ROM into the Speed Density "insert scaling section" and also the MAT section too.

Testing:
You could always leave it wired in and test temps with your car logger putting direct heat on it etc ...if you put the correct values then you shouldn't have to worry about bench testing.