Can someone look at my datalog please?
 

I have a weird issue after startup, once the car starts the revs fluctuate wildly for a few seconds then level out.

At first glance it seems like Afterstart enrichments that are at fault, but the revs steady out before the ASE timer ends, also I've tried faffing around with the ASE settings and it didn't make one jot of difference.

I've a suspicion that my IAC is broken, (which would also explain the high idle I experience when freshly warmed up, (but not heatsoaked)

I've attached a datalog of my car's startup, and a copy of my MSQ

Thanks all

Try normal MAP instead of fixed MAP during ASE.

Jim

Thanks Jim, I'll give it a whirl :)

no intake temp?

fuel numbers seem really high....I'd scale the table so you have less rows in boost and more under 100MAP for more fine tuning at idle and cruise, boost needs little help.


It looks to me like when the revs were bouncing it's cause it was hunting for a spot to idle at, but since there is just sooo much fuel it's not doing a great job.

FWIW, I have 7 non-boosted rows. 20; 26; 35; 55; 75; 84; & 100MAP

I have this problem as well but it goes away after a little while i think it is the warmup wizard try setting the values there to 100% wich = 0 compensation. I am not on a pc with MS on it or MLV, right now so i dont know just how bad you idle is. But mine hangs aroun 1300 amd goes down to 800 and surges intermitently. So far i have zerod out the afterstaret erichment and warm up and it has helped. If the base settings are good i would look into the AIC code to see if maybe the control algorithim is set up correctly. Wich will be my next step as well. GL Also a Vac leak can make it hunt like this as well, wouldn't hurt to check that while you are at it.

the idle is fine, when it starts up it bounces up and down a few times before leveling off...so I think the IAC is fine...however you notice when it's doing it you're at 10:1 AFR.

...the amount of fuel you have in those spots is more than I have in some boost rows.

your spark also needs a bit of work in boost, right now it looks like you have an N/A spark table that the MAP values were just changed on.

So boost/vac leak then?

Checkout the constant 80kpa while the rpm is fluctuating. I think that provides a hint.

Jim

good catch.

I would first remove all after start compensation, then check for vac leaks also i found putting my first row for RPM at 700 rpm helped me abit as well.

Jim, top notch, just changed that little dropdown menu and all is good in my world again :)

that'll teach me to try someone else's settings ;)

I know it's weird isn't it, but after repeated beatings on the track and street it's fine, no knock etc. :bigtu:

Even used a set of detcans to make sure my hokey Knocksensor attachment is causing an issue, all was good :)

LC-1 still in warmup at that point, so no usable signal ;)

Glad that everything is ok! :)

Jim

so what did you change exactly? i am having similiar issues with my 550's but i habg at 2K until i hit about 40+ C on coolant temps my AF reads good vac is good. this is pissing me off i also get about 200 rpm surging at idle now.

there's a timer in startup. You can make it stay at a set MAP value for a ceratin length of time during startup.

see afterstart enrichments. if fixed MAP is set, the it will sit at that kPa untill the timer ends...

i bet thats what you have, change fixed MAP to normal MAP.

here is a pic of my afterstart enrichment page it looks to be set to normal.
Attachment 216284

So anybody else got any ideas?

so basically you idle at 2K untill 40°C?

try turning your warmup wizard values to all 100. But when you have you next cold start, see where it's reading the AFR, and turn the number up untill youre around 12:1 AFR.

tried that makes it harder to start. still sticks. afr looks good 13-1 most of the time then when it calms down it is stoich. If i turn on the ac it goes down towards 1k rpm but still surges 200 rpm or so. I wish i could find a way to get better control of the stepper motor, i think it is a problem of it opening to large to start and not droping correctly.