Alot of cobalt guys have been having problems with there IDC's doubling and this cause's the afr to go in the toilet. I'm posting a couple logs of this problem. One is in speed density (where there is no problem). The next is with the maf enabled on the same tune (IDC double's at WOT). I'm not sure exactly what table we need, but one thing I've noticed is that the biggest spike is always at 9900hz. Lets see what you guys can come up with.
Last edited by fast98; 04-17-2008 at 09:53 AM.
would you mind posting the cooresponding .hpt files for both the maf & SD scanner logs?
It doesn't have to be perfect, it just needs to be done in two weeks...
A wise man once said "google it"
I used the same tune for both logs, only difference being I set the maf fail frequency to zero for speed density.
well my car developed this problem tonight
04 Saturn ION redline
3.1" Pulley, stage 2 belt, 42.5lb injectors, Front mount H/E, Custom intake, Water/meth injection (5gph nozzle) Custom Fuel return line, Aeromotive FPR, Walbro 255 pump, -6 line all the way back.
On the log it happens at 3000, 3500, 4450 timestamps..did happen log because once I felt it i got off the gas.
BTW this is a very very very rough tune, just got the return line done last week and car has been driving great until today when this problem occurred when trying to get a decent tune out of it. Stock stage 2 timing BTW, VE table is messed up and haven't had a chance to clean it up at all...all tuning was done maf wise
also you will notice my AFR's go super rich when this happens, not lean like Dj
Tried failing the maf, but it still did it, just didn't jerk as bad, but my comp was dead so i didn't get any logs.
really besides the MAF, the only thing i changed between when it wasn't happening and when it was happening was COT, and Piston protection??
Attachment 11717
Attachment 11718
Last edited by Ryze; 04-14-2008 at 11:31 PM.
okay now I'm digging into this, when my car starts to do this, for some reason Commanded AFR drops to 7.xx:1 AFR??? then AFR doubles, actual AFR drops to 9.xx:1..So looks like i'm getting to much fuel, but why does commanded drop like that?
What I'm seeing similar between both our tune's but also different is the COT protection. I changed the COT adder max and min to 1.00, while yours is set to 0.00. Could this explain why my car goes insanely rich and yours gets extremely lean, but are doing almost the same thing?
Last edited by Ryze; 04-15-2008 at 12:09 AM.
yours is likely COT, set the max adders to 0Originally Posted by Ryze
I count sheep in hex...
I don't even remember why I upped it up to 1.00, i know i had a decent explaination at the time, but I guess driving around for 6 hrs straight doesn't allow me to think clearly..
ok a few things to help here. firstly please set the P0103 DTC to 0 - MIL on 1st error, or 2 - No MIL, that way it will go to SD correctly. Having it set to MIL on 2nd causes fucky behavior.
To me it looks like your VE table is too lean at lower RPMs (when the airflow code looks at both MAF and VE) and when the airflow code switches exclusively to MAF at higher RPM the AFR comes rich as expected.
You need to be sure you are in SD mode by changing the DTC as above. You should see P0103 in the DTC's in the scanner and your engine light should be on.
Chris...
I count sheep in hex...
Thanks chris. I changed the DTC like you suggested. I have tried many many different MAF cals and VE cals. I've tuned them seperately then i tuned them both in SD, both with no change. I'll go out and re-tune the VE and the MAF as you suggested and I'll report back later.
chris I did as you said and still no change. Ill just fudge the maf table for now till this gets fixed.
fast98 please try this file and post the .hpl file gathered from it.
Thanks,
Bill
It doesn't have to be perfect, it just needs to be done in two weeks...
A wise man once said "google it"
Bill I was gunna send you a private message but i dont see the option. Anyways I dont see anything changed in that file, is it something I dont have access to? There are a couple changes I made since I last posted up that file, Its one of the older tunes. So can I swap over my new tables without affecting anything you might have changed?
Thanks
Josh
Yes, it is something you don't have access to, you can swap over the new tables, however please post the new .hpt file with the .hpl file you post.
Thanks,
Bill
It doesn't have to be perfect, it just needs to be done in two weeks...
A wise man once said "google it"
Thanks a bunch Bill, I'll work on it tonight and post up tomorrow.
Josh
And the verdict is?
It doesn't have to be perfect, it just needs to be done in two weeks...
A wise man once said "google it"
DUNDUNDUN
Quick question, how would we diasble the blending and run soley maf? Raise or lower the rpms?
Lower, thats actually what I did with his file, lowered it so maf takes over starting at 3000 rpms, if it cures his ill's I figured it would fix most of the other peoples ills that are having the identical issue.
It doesn't have to be perfect, it just needs to be done in two weeks...
A wise man once said "google it"
Thanks Bill!
Its fixed I lowered it down to 2400
Bill you should also add in your sticky in the 4 cyl forum, that lowering this is the best way to tune the maf. I tuned the VE table and the MAF many times and could not get it to go away. I tried complete open loop tuning with everything disabled and I got nowhere. Thanks for the help getting these tables added
Last edited by fast98; 04-18-2008 at 01:53 PM.
Great to hear!
It doesn't have to be perfect, it just needs to be done in two weeks...
A wise man once said "google it"
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