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LTIT Slow or immobile need input...

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Old 07-08-2005, 10:03 PM
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Default LTIT Slow or immobile need input...

I have noted my STIT is cruising around, say -3.00 g/sec average, the LTIT in P/N after 15 min of logging moved from -.08 to -.11 lb/hr. In gear, the log hasnt moved yet, seems stuck on -.07 lb/hr.

I have adjusted the enable learning temp to be lower than the normal op temp, IIRC its set to 155*. I would expect anything over 155* that the LTIT would start adjusting? Am I needing to adjust something else to get them closer to zero?

TIA

Charlie
Old 07-09-2005, 10:53 AM
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guess I will start looking at the Min'Max values and see whats up.....
Old 07-09-2005, 05:15 PM
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mine dont adjust until it sits at idle for about 10 min or so, i noticed this when idle tuning. might wanna give it a shot, mine are down to 0.07 on the ltit and should be lowe rwith the next tune
Old 07-09-2005, 09:30 PM
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How the hell can I let it idle for so long with Fans disabled? Get rather warm after 6min, 190*. I guess I could try a shop fan to blow across the radiator.

I was wondering if the boundaries or something may need adjusting but they seem to fall within the Min/Max area.
Old 07-09-2005, 11:06 PM
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hmmm i have never really messed with it, i let mine run that long and it gets to about 80*c , the fans kick in but i never really had problems with it
Old 07-09-2005, 11:23 PM
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If your RPM range exceeds 60 at idle ( say RPM range of 825 - 915 ) then try bumping the "Update RPM Error MAX" value. 60 is what my stock value was - yours may be different?

Eng -> General -> Idle RPM -> Adaptive Idle RPM -> Update RPM Error MAX.
Old 07-10-2005, 03:53 AM
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Bink, yeah, I'd say my rpm range needs to be adjusted then since the damn thing swings from 700-950, which is why I am trying to tune idle before VE and MAF are complete. I had it pretty before the heads swap, or so I believe. Will adjust that range, as well I am comptemplating raising my idle from current 875 to 950, as I noticed in VCM Tools 950 was pretty smooth.

Also, as a side note to this, if I go into the IAC Steps (VCM Controls) and adjust it up to 100 and it idles perfect, what am I supposed to adjust? Or would I need to open the TB Blade more, then offset the Effective Area again to account for the increased airflow?

TIA

Charlie
Old 07-10-2005, 08:53 AM
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what size cam do you have? if you ve is off in the idle cells it will throw your airflow numbers off a good bit. ive got a log that i use for tuning all my idle stuff and the only thing i have yet to fix is the cold start rpms that drop for 4-5 sec, but im still trying to work on it. give me your email and ill send you my config. if you want
Old 07-10-2005, 11:54 AM
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cat3n4@gmail.com

TSP 231/237 .598/.595 112*, in 2000 A4. I am sure the VE is off, as well as every damn thing else.
Old 07-10-2005, 12:31 PM
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alright i sent them to you. ive got the f13 so its kinda close with yours and what i was doing helped. you can send me your bin as well. ive got 55 tunes of data for idle with my cam and i took notes on what did what so i can look at it and see if your problem relates and any way
Old 07-10-2005, 01:16 PM
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Thanks, have some welding to do this afternoon, will get back to you tonight on the files and possibly sending some .bin your way. I am sure, since all the feedback points to it, the VE, then MAF, then Idle can all be retuned. My hesitation is, I am swapping engines, with larger cam shortly, so kind of want to start now, at least get it closer, but as the same time dont. Appreciate the help.
Old 07-10-2005, 03:42 PM
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Originally Posted by Bink
If your RPM range exceeds 60 at idle ( say RPM range of 825 - 915 ) then try bumping the "Update RPM Error MAX" value. 60 is what my stock value was - yours may be different?

Eng -> General -> Idle RPM -> Adaptive Idle RPM -> Update RPM Error MAX.

Adjusted the RPM Range from 60 to 200, started logging, and instantly the LTITs started moving. I love all the little supportive items that assist the issues at hand but are rarely addressed!
Old 07-10-2005, 04:51 PM
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so what exactly does that table do? but are you still having the issue of surging rpms?
Old 07-10-2005, 05:01 PM
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I ran the excell sheet for relearning the running air flow on a G5x4 cammed car, i disabled the fans and ran it up to 220* before cutting the process. Its results reduced the RAF numbers by about half, I loaded into the pcm and the results were bad, it would start right up then die, or surge than die, never improved after driving around either. I decided to put the stock values in and it runs great. go figure. I'm almost tempted to do the opposite of whan the findings suggested and raise the numbers over stock.
Old 07-10-2005, 05:08 PM
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my numbers are barely higher than stock. i used to have rpm dips with light load or small throttle change but now they are all gone. i dont like files that do it, i like to check the data out myself and make changes by hand, takes a while but man the car runs just as smooth now with the big cam as it did stock. you can hear the lope but it drives great
Old 07-10-2005, 05:20 PM
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I lowered the RAF before with not so nice results as well, I contribute it to the different ways of tuning. For me, with a hogged out TB Blade airbleed hole, and making changes on other parameters, the RAF I believe needs to be higher. However, I am sure the process works, if you start tuning from basics, rpm, trans settings etc, then go to VE, MAF and lastly cover the Idle parameters. Might some day revert to stock tune, and go that way to check it out.
Old 07-10-2005, 05:34 PM
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Mike, sent those logs to you. Let me know if you want the tune .bin file as well. Wouldnt it be nice to have a list of "(insert parameter here) if adjusted higher = (list outcome AND any associated parameters it needs to change to work right here), or if adjusted lower = XXXX. I need to start writing myself notes, and searching more topics to piece meal all this info together. I know it is not so often you can adjust delay without decay, and IAC w/o Eff Area etc...
Old 07-10-2005, 05:57 PM
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I had already done all the basics as well to help it idle with such a low vaccume, tune the VE, decay delay, cranking ve, afterstart enrichment, idle timing ect ect.

At first we used the TB blade set screw method for allowing more air in, imop its a hack method at best. We followed the steps to properly testing and setting the voltage each time, however every time after resetting the tps sensor it we default back to 3% tps at idle after two driving cycles. He ended up closing it and drilling the TB, idle is much improved.

The only time the car wants to surge is rapid off idle and return to idle throttle changes, such as pulling up hill into the garage, ect. I think i'll try to increase the table slightly and see if I can rid that.
Old 07-10-2005, 06:01 PM
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go ahhead and send the bin file to me so i can compair it to mine too
Old 07-10-2005, 08:47 PM
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welll it opens in excel, if you can send me the hpl file i can check it out better in there. from the looks of it your effective area has the right curve to it but it needs to be offset some. from what i see i think we can get some things straitened out pretty easy



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