Gentlemen,

I spent four glorious days at VIR but had a couple of issues. Here's one...

The temps were considerably lower than the tune had been compensating for. She likes to idle at 13.7, and the tune had her at 12.5 or so during warm up in normal Summer temps. Now, ambient temps were in the mid-40s and start up was rich, down at the mid-10s. No other tune changes, so I am ASSUMING this is temperature related. In fact, the whole tune seems to have gone rich in the lower and cruise areas. She was hard to start, so I reduced fuel in the VE table by about 10 units--from ~70 to ~60 in the idle boxes. That helped, but didn't fix the issue, so I also reduced WUE. She was easier to start, but not fixed. And after the changes, when she's warmed up, she idles in the high 15s.

I have EGO Off in the log on purpose. At the very end I'm pulling in to get gas. The car is fully warmed up and you can see the high idle AFRs.

I'm sure this is my fault, part of the tune. Any help would be greatly appreciated.

 

Pretty normal. The ECU applies a temp correction, but it's not perfect. I generally do a bit of autotuning to help this and give EGO about 10% authority.

 

his gammae is 100% through that log.

 

You're talking about the Boyle's Law curve provided with the base tune? I have that at 100% across the board as it was screwing everything up.

I would have thought the denser cold air would cause the tune to go lean. If I have that wrong, please let me know because that presumption has me scratching my head about what's happening.

 

Over the last coupe of days, I've been scratching my head, knocking back some IPAs, and staring at the tune. The only thing I can think of is that the huge Flow Force Injectors are passing a lot more fuel when the fuel is also more dense from being cold, than is compensated for by the air being denser. If that's the case, then I just need to be ready to deal with it a couple of times a year.

Anyone care to comment?

Thanks,

 

yeah, that's nonsense.

maybe stop knocking back IPA's and start reading/learning '

The reason your numerous threads don't get much attention is because you just keep asking basic questions without showing any proof that you've done any actual research/leraning, and people don't want to constantly spoon feed you.

No offense.

 

I'm gonna throw you a bone:

make sure your air density curve is sloped such that you're adding fuel in proportion to temps dropping

 

But the temps dropping made the tune go rich, unless it's just a coincidence. Hence my post.

 

right, if the curve is too steep it will add too much fuel.

 

It's still flatlined at 100% right now.

I was having the issue where, for example, in the heat of the summer if I parked the hot car for a few minutes to run an errand, when I came back and started it, the AFRs would shoot up into the 16s for a few moments. The curve provided with the baseline tune was just making everything worse, so it was going to be the last thing I messed with. She's been running fantastically since DIY repaired my box. No idle issues until the temp dropped, so I assumed there was some relationship. The tune should have gone lean in the cooler temps, and it didn't. I'm stumped because nothing in the tune seems out of place to my apparently still noobness. So I asked the experts.

I'm humbled you took the time to answer.

Thanks,

 

well that's problem number 1....of like 100

a car running in different temps will need fueling temp corrections.

 

Sure. But the baseline curve provided is ridiculous. Given that my curve is flat, which of the other 99 problems would cause the tune to go rich with decreased temps?

I'll PayPal you beer money so you don't feel like you're spoon feeding me...

 

I'll do you one better: you want me to e-tune your car? PM me if so. It's "fancy craft beer" kind of money, not free lol

But to answer your question:
yes the baseline is ridiculous. It adds too much cold and pulls too much warm. Way too extreme for most people.

But having it flatlined is only good for a temp solution while tuning, usually just 1 session. So you note the temp when tuning the car, tune the car with it flatlined, then either adjust the correction and ve tables to reflect one another (like having it pull 5% in the correction but then add 5% to the ve table), and extrapolate the rest of the curve to work in different temps. orrr you set up a more realistic correction curve, tune the car, and then let EGO correction update the rest if it's not too far out.

Hope that makes sense.

I've never seen a car that wanted more than about 120-125% when dead cold, and I've also never seen a car that needed the correction to go below 100%. Cause at that point it's counter productive and fighting itself .

Of course this issue is further compounded by different units having different logic applied to air temp corrections. So there's that too (ms2 and ms3 are different iirc).

*Edit: also I didn't look at the tune you posted cause I'm at work. So I can't comment on the other 99 issues. I can glance at it later when I'm home.

 

I'm at work also.

I would only allow you to buy craft beer with any funding I provided.

I was not too concerned with the curve. My last event is usually the first week of Nov, and then she goes into the garage till late Feb-early March.

 

it still seems weird to want to have to pull fuel in cold temps, that's normally never the case..

 

correct. definitely something else wrong with his tune as well
maybe his spark temp correction is retarding a ton. or bad injector settings. or........haven't looked at it yet