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-   -   lower temps leaning out my fueling? (https://www.miataturbo.net/megasquirt-18/lower-temps-leaning-out-my-fueling-21228/)

Mach929 05-19-2008 07:43 PM

lower temps leaning out my fueling?
 
since my switch to hi-res, saturday i did 2 good logs and ran the ve analysis and my fueling was great, drove 60 miles here and there with my girl, everything seemed great. Today temps were 20 degrees lower and i was much leaner eveywhere under normal driving. now apparently i suck with this megasquirt but what could cause this?

turbobluemiata 05-19-2008 07:59 PM

just switching to hi-res leaned out my whole ve table 2

Mach929 05-19-2008 08:00 PM

yes but i redid my whole ve table at 70 degree weather, park the car, drive it today at 50 and i'm like 16:1-18:1+ in places when i was 13:1-15:1

Joe Perez 05-19-2008 08:11 PM

What does your coolant-related air density screen look like?

Mach929 05-20-2008 01:24 PM


Originally Posted by Joe Perez (Post 259299)
What does your coolant-related air density screen look like?

it's exatly as it comes from diy for the mspnp

Atlanta93LE 05-20-2008 01:27 PM


Originally Posted by Joe Perez (Post 259299)
What does your coolant-related air density screen look like?

Indeed. I bet you tuned your ve table while richening was occurring due to "high" IAT. The diy base map has quite aggressive "coolant-related," or IAT-based fuel adjustment.

wes65 05-20-2008 01:34 PM

if the IAT fuel adjustments were too agressive then wouldnt that make it overly rich when it got colder? Colder air = more air molecules = more fuel needed. So, if it was over compensating, it should be rich. I may be off here but i think thats right.

Braineack 05-20-2008 01:37 PM

well it's easy to see on your logs if enrichments were in use...look at the Gammae (total enrichments) or Gair (air temp enrichments) to see how much enrichments are there....if its rich and you see like 110 or something, your map is good but its adding too much fuel for some reason or another.

ThePass 05-20-2008 01:54 PM

What do the Gair and Gammae numbers mean? I noticed that in MLV mine range from 150-90.
-Ryan

Braineack 05-20-2008 02:00 PM

the amount of enrichment. 150 would be 150% or 50% more fuel under that condition...but this will include warmup enrichments....

ThePass 05-20-2008 02:12 PM

So a 97 would mean... 3% is being pulled..?
I'm hovering around 145 when cruising lightly and light accel but half throttle or more it drops to 110-95. This means my VE is good?

Braineack 05-20-2008 02:29 PM

My Gammae sits at 100 almost all my logs after i reach 160*F (warmup), it dips up/down when EGO kicks in. and rises to 110-130 at idle when i start to heatsoak and start to see +20*F higher intake temps than ambient while cruising, I have AIT corrections turned on at idle to keep my AFR solid.

Mach929 05-21-2008 11:11 AM

1 Attachment(s)
here's my map. i'm not really sure what i need to play with. i guess i'm stuck on the concept that if it's colder out it should richen up the mixture but for some reason it's leaning it out. at least that's the way i think it should work in my mind. today, a bit warmer out run and drives great.

anyway if one of you gurus could take a look at the map i've got in there right now and make any suggestions that would be great.

wes65 05-21-2008 11:19 AM

It should add more fuel to keep the mixture the same. It shouldnt be richer or leaner. It's not adding the required fuel and therefore, it is running lean.

Mach929 05-21-2008 11:19 AM

1 Attachment(s)
and here's the datalog i made just driving around to make the above ve table, i see gair and gego but i'm still confused on how to use them, i'm guess i gotta disable those things, let the car fully warm up past 160 and then redo my fuel map? if so how do i turn those things off?

Matt Cramer 05-21-2008 11:25 AM

Was the hi-res code you loaded already EasyTherm'ed for the temperature sensors you're running? If it is set up incorrectly for the IAT sensor you have, it'll do this and not give you too many clues in MegaTune as to what's going on.

Mach929 05-21-2008 11:31 AM

i thought it was i took the firmware image from the link in this thread and followed the instructions
https://www.miataturbo.net/forum/showthread.php?t=17901
i thought it was supposed to be already easythermed

Braineack 05-21-2008 11:31 AM

Watch your Gair during that log...all your enrichments are intake air enrichments....i could see cooler temps leaning things out, you can see the enrichments kick into +120 when you near 3K, due to your air density correction map. From +50°F AIT you add fuel between idle and 3K.

For example, watch at 1938sec till 1972sec. You come to idle, where you are adding 33% more fuel (Gair) to see your 14.7ish idle. If the intake temps weren't as high (80*F) you'd be adding less, so leaner....

Mach929 05-21-2008 11:41 AM

i must retarded, i get what you're saying here but i don't know where to go to fix it

Braineack 05-21-2008 11:50 AM

go to clt related air density, i believe it's under advanced...

make everything below 80*F 100. I correct for heatsoak at idle. see if that helps. you'll probably need to retune the idle cells.


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