Found issue.. corrupt file.
Idle stumbling?
Found issue.. corrupt file.
Last edited by 1080112520; 01-22-2012 at 09:44 PM.
2009 chevy cobalt ss turd. to many mods to list and to many problems to fix...... errr previous owner
i DID LOWER THE RPM FROM 950 AT 172 because im wondering if the load at idle is to much. Because i know theres a few factors to get the idle to be constant, as in the load and ect.
2009 chevy cobalt ss turd. to many mods to list and to many problems to fix...... errr previous owner
Wow.
That's your tune?
why do you ask?
2009 chevy cobalt ss turd. to many mods to list and to many problems to fix...... errr previous owner
LOL, whats so bad considering everything was fine then it just started . his is a 24lbs tune i made and it also put down 356whp
2009 chevy cobalt ss turd. to many mods to list and to many problems to fix...... errr previous owner
Yeah, this is my car. Runs great, no hesitation anywhere, makes great power. Just that damn idle is very bouncy and we cant figure it out. Only started after we switched to E. All fill ups on E have been from the same station except once (which was the last fill up) but the problem has been since the switch. I have a buddy that fills up at the same station and he has no issues so far.
I've tried to take video but with all the background noises of everyday life, it's very difficult to discern.
Any ideas anyone?
"Runs great" is a relative term. Meaning one person's idea of running great might be very different than another's. I can tell you one thing for absolute sure- your issues are 100% tune related. The tune is causing the idle problem, fix the tune and you fix the idle.Originally Posted by Frogstofall
Here's what an LNF should idle like, these are from this morning. First is a 37* IAT cold start (E47) and the second is a warm idle.
Nice and smooth
Very Nice GMTech.
I havent quite got LNFs like that but the idle doesnt bounce or anything as the OP states.
If I was near my lapotop, so I cant see the OP log, or I could probably point to the problem in the tune. Ill try to post later.
Last edited by HNRClothing; 01-13-2012 at 11:08 AM.
Well here's the thing.. the issue occurred after I think 4 revisions, and if you cruise and then come to a idle its fine. But morning startup its decent. It still fluctuated about 2-4* in timing. But this log I think was with the new revision added on with no driving or anything just idle. I'm not asking to to get opinions on the tune. I'm asking for the observations on what it could be. Have i been able to get Lnfs to idle smooth very mush so. This tune itself is fine, it boost correctly and I correctly get what I'm commanding. Other then idle. but getting down to what's causing the issue is what's getting me.
2009 chevy cobalt ss turd. to many mods to list and to many problems to fix...... errr previous owner
Because stating its somthing the tune is causing without getting a reference is basically like saying yep somthings wrong but its the tune when in fact there's other factors to take. So what my question is what do you think is causing it. This is the first time I've expereinced it. I have changed the.timing multiple times.along with the cam timing .. but does the same.exact thing..
2009 chevy cobalt ss turd. to many mods to list and to many problems to fix...... errr previous owner
OK, here are the specific tables that need work to fix this problem. Some would be better put back to stock, some need massive smoothing, others just have numbers in them that don't make sense and DO NOT work properly with numbers like that.
The tables you need to work on are...
Target Idle Speed
MAF Frequency
MAF Calibration
DALS
Injector Control- Injection Angle
Main Spark Advance- all tables
Those tables are the biggest problems with the idle issue. There are many other tables that could be fixed/optimized, but you're asking about the idle specifically.
Thanks everyone for the input.
Gmtech, I guess by runs great I mean it feels great while driving and makes pretty good power. I appreciate you helping us out. Your idle looks puuurrrrty.
Target idle speeds been changed, maf cal and maf correction is spot on. The.correction table is jaggered and not smoothed because I've seen better results keeping it like this snd not smoothing. The dals have been changed a couple times to stock and also a little less and still nothing. Timing was changed a few times as well, on the bottom end betwen 0-20% load for idle and I did notice it helped a little but still timing and etc actual were jumping around. I'm having another guy use this file as a base and the idle is perfect. He's e47 and ect as well. I know two cars are not the same but seeing this happen after the 4-5 revision its leading me to somthing else. Only thing changed in the fourth revision was maf calibration. And once revised after log trims were close and everything is doing what's commanded but the timing changed and the etc....
And gmtech i appreciate your help... This is the first ever issue I've had.. so thank you.. ill try some stuff out and get back.
In case anyone was wondering what a full throttle pull on an LNF should look like, here's one I just did today. (Chart zoomed way in of course.)
Started with a nice smooth building 26.2lbs boost at 4500, held pretty flat to 7500rpm where it was 27.5, then a reasonable spike on throttle shut off of 29.7psi. VE and MAF very smooth and parallel the whole way, which is ideal. Max wideband variation was less than .02 Lambda over the whole pull, injectors and fuel pressure within reasonable levels and smooth with no dropouts in pressure or spikes in duty cycles. This is what to strive for. Anyone else with a log like this post it up. Yep, the 3.654 is the 60-100 et. Not my fastest but I'm also being conservative on boost levels. Top down in a Kappa also.
Sweet deal, ill have to post my 60-100 but I usually just spin .. so its pointless
2009 chevy cobalt ss turd. to many mods to list and to many problems to fix...... errr previous owner
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