Agreed. This is why I was looking for some sort of setting to adjust.

The MAT sensor is currently connected to the IAT circuit Pin 72 on the MAF harness. (Red w/Blue stripe) And the MAT sensors ground is connected to the black ground wire right next to pin 72 on the MAF harness.

Apologies, that is logging request 3A in Evoscan. Not quite sure why I highlighted that.

 

@mrfred
So I was digging around and noticed that there was a 'MrFred harness' for active baro through spoolin up. I did some more digging and couldn't find any information about this. Is there a connection that I can make on my own? Would anyone happen to know where I can find this information? Thanks.

 

An OEM MAP sensor is used. It requires a special SD patch that has not ever been widely distributed. If you drive at varied altitudes, it would be a good thing to have for offboost drivability where idle can be affected by barometric pressure.

 

i'm also running the active baro harness, is there a way i can get that code to add into my xml? i'm using the 9653407 SD 2.0 rom.

fyi, my car has never run as good as it does now and i'm still tweaking my VE table on SD 2.0
thanks to eveyone who helped! it's alot of work but well worth it, the car is turning better times every tuning session i put into it.

 

Hey guys, I know this specific thread isn't very active anymore but I've been searching all night for information on the issues im having with my SD Tune on my Evo 8 and it led me to this thread, hoping I can get some help.

I'm on SD Rom 94170115 and am experiencing a lean condition at take off. I've read quite a few threads on this issue but they're all quite old and don't have a definitive fix. This lean condition happens when taking off from a stop, if I let the revs fall below or near say 1200rpm it goes full lean on my AEM wideband and the car just chugs unless I shove the clutch in. I can rev it high or ride the clutch quite a bit to get around this issue but it's rather annoying, especially when trying to take off fast for traffic.

My second issue is a stutter between say 2000rpm-3000rpm when cruising at light throttle essentially in any gear. If I'm increasing speed with more than light throttle it's not really present. Again I've read others with this same issue but the threads were old and had no definitive answer. I notice when this stutter happens the AFR's blip lean on my widebane, like 15.6afr or so and only for a split second. When the stutter happens I can not only feel it but I can hear it, the exhaust note/engine sound changes briefly.

3rd "issue" is that cold start is rather rough. For the first 10 seconds or so it's nice and smooth and idles around 1500rpm and then like a light switch it'll go real lean, then start to correct and go rich, then go lean, then rich, etc and seems to misfire while doing this. It does this for about a minute then just idles around 1400rpm until it's at temp.

For the record, I'm not tuning the vehicle but a friend who's a reputable builder/tuner is and he's never ran into these issues, im only his 2nd SD tune I believe. I'm just looking for insight to pass along to him.

 

Here's my take on your 3 issues:

• First one sounds like you need more fuel. I'd add more fuel via the 3D VE map first in the areas where you are taking off from a stop and if that doesn't work, try tweaking the AE maps.
• Second one is similar to the first one. Try add more fuel in the areas where you experience the stuttuer first then tweak the AE maps if you have to.
• Your third issue sounds like a start up fuel issue. See Start-up Fuel and ISCV Tables.

 

Thanks for the quick reply! I know at one point my tuner adjusted the VEMAP per my request as that's what I've seen on other forums/threads but when he did that it made light throttle/light load go very rich. Say I'm getting up to speed from a stop, basically any throttle to increase speed would immediately go very rich, sometimes as rich as 10.0 when not in boost and simply trying to get up to traffic speed. It makes sense that issues 1 and 2 are related though because when he adjusted the VEMAP the take-off lean condition improved but the stutter got worse. I notice when the stutter kicks in you can see the AFR's go lean for a brief second, you can hear and feel the stutter when it happens.

Sounds like a lot of fueling issues, I'm seeing him today after work and hoping we can finalize the tune as we've tried several times to get rid of the above issues with no good results which is what sparked me to make my post.

 

No problem. Since you said it goes pig rich when you step on the gas, in your case your tuner needs to take away fuel.

 

So then whatever he adjusted, in the MAPVE, was simply just too much then I'm guessing, he added too much fuel.

I keep referencing to this thread where John from English Racing states "Lean issue is caused because of the adjustment at the 99kpa side (9653's for reference, poet 8). See how the right hand is at 92. This means it corrects lean, needs to go the other way like 102 or 105 or more. All in the MAPVE setup, Asynch Delta can be left stock and this can be correctly tuned for all RPM based on that table."

https://www.evolutionm.net/forums/ec...-sd-rom-3.html

The reference he's referring to is the graph below:


This area is what i suggested to adjust and showed my tuner but I'm not sure what he actually adjusted. If he did adjust this exact spot, it did correct the lean take-off but then brought on the rich part-throttle.

 

Yes correct. However it seems you are working with the regular SD patch and not the SD 2.0 patch with the 3D VE table. If that's the case, you just need to adjust the MAP VE and RPM VE tables. No need to mess with the MAF compensation table unless you know what you are doing. Adjust the Asynch delta table as a last resort only if you can't fully dial in your part throttle issue by playing with the MAP VE, RPM VE, and High Octane fuel tables.

 

The image of the graphs was one that someone else posted from years ago with my same exact issue, just wanted to clear that up. Those graphs are NOT from my tune/ROM.

 

Just to update, I met with my tuner Saturday morning briefly and he adjusted some numbers in the MAPVE table and sent me on my way. It did more harm than good so I turned around and had him put it back how it was before. Unfortunately at this point in time I think I'm going to look for a new tuner which not only sucks because I've spent a good chunk of money on the tune but because they're friends of mine.

 

Probably a good idea to take it to someone who knows their way with ECU Flash. It's not exactly the most user-friendly interface and it takes a while to get familiar with. Good luck and report back with your results.

 

For sure, they are very reputable with MAF tunes but myself and another friend were there first SD vehicles. My friend's Evo 9 is damn near perfect tune wise but mine has several issues. Thank you and I'll be sure to report back!

 

If your tuner was able to dial in your friend's car perfectly but can't do yours, you might want to check other things on your car before going to another tuner. Check your fuel system, sensors, boost leaks, etc. There could be another problem that is making your car act weird. Worst case scenario would be to go to another tuner who won't be able to fix your drivability issue due to an underlying problem.