Cold Start Enrichment in pre-2003 COS

[Alex99]

I just stumbled across the same problem with the ECT enrichment table A0008not working as others have before.
I'm using COS3 in a 2000 Corvette with a 02020003 calibration. Unfortunately the updated calibration that was provided earlier ( http://forum.efilive.com/showthread.php?t=4285 ) isn't working for my COS since mine is a 2002 COS.
Is there a way to update the 02020003 cal also or can you suggest a work around solution?
Could a switch to COS5 get rid of the problem? Is there an OS for the Corvette for COS5 (I only know the one for F-Bodys)
I live in Michigan and the winter is coming close and I drive my car daily, so I would need to have some kind of cold start enrichment in the next time.

Thanks
Alex

[Alex99]

Anyone has an idea how to solve this issue? I've searched through the archives but couldn't find anything related beside the known problems with the 2003+ COS.
Thanks Alex

[Alex99]

Small update on my problem:
I upgraded my COS#3 to COS#5 (2020005) yesterday to see if the OS was the reason for the lacking function of the A0008 ECT enrichment table.
It was not the reason. Still, the enrichment on cold starts isn't working, so I guess it has other reasons to behave like that.
Is there anything that enables/disables the functions of the COSs? My IAT adjustment table A00014 works very good though.

[smokeysbandit]

Hey Alex,
Unfortunately I don't have an answer to your problem, only my sharing in your problem. I posted with the same issue about 2 weeks ago with no responses. I'm sure if you check out the log included with my post it will look very similar to what you are experiencing. In the mean time, TTT, and I'm subscribing. If you want to take a look at my tune for comparison, it is here: http://forum.efilive.com/showthread.php?t=9064

[Alex99]

Thanks for chiming in! There are obviously more than a few people having this problem. The user hpcubed seems to experience the same.
Right now I used the temporary fix that was suggested by Whippled 496 (see http://forum.efilive.com/showthread.php?t=4224&highlight=ect ) to have at least some kind of cold start enrichment. It works ok but is of course just a bandaid. Being able to use A0008 as it was designed, would be much easier and accurate.
I'm driving in OLSD mode. Do you use your MAF sensor?
Which calibration do you use? I see that you also have MY2000 vehicle.

[Alex99]

To the EFILive staff and admins:

Are there any plans to investigate the above described problem or do we have to deal with it ourselves without customer service?
Any response is highly appreciated.

Thanks
Alex

[Blacky]

Looking at it...
Regards
Paul

[Alex99]

Hi Paul,

did you had the chance to look at the problem? If you need more log files with the problem, let me know.

Regards, Alex

[Alex99]

Any news regarding the problem?

[driver456]

I just happened to try {A0008} today and it worked for me and I have a 97 C5 upgraded to a 02pcm and upgraded to COS#5.

[Alex99]

Would you mind to provide your tune so I can compare it to min to see if there are any obvious differences?
Might also be interesting to the EFILive folks.

[smokeysbandit]

Hey Alex, did you ever get resolution? I'm still having my issues with cos5 doing this, even after completely uninstalling efilive, updating firmware, and reloading the os, then the cal.
Thanks,
Brandon

[Alex99]

Hi Brandon,
Unfortunately no resolution of the problem here. I am pretty disappointed by the lack of support by EFILive, but what can you do other than asking politely several times?
I got through the winter by adjusting the after-start enrichment, but this is obviously just a band-aid solution for the real problem.
Alex

[Blacky]

Hi Alex,

Firstly my apologies, I dropped the ball on this one. I could not see anything wrong with the configuration of the A008 cal when I looked at it late last year. I meant to get Ross to take a look, but did not. I've sent a message for Ross to take a look at it now.

Regards
Paul

[GMPX]

Can you confirm that changing the values in B3647 results in AFR changes?
I looked at the COS code again and B3647 is multiplied by A0008 directly after the AFR / EQ value from B3647 is calculated.

If A0008 is not working at all then I can only assume that the PCM is not using B3647 which would mean it is not in Open Loop.

Cheers,
Ross

P.S - I'll keep an eye on this thread until it's solved this time :redface:

[Alex99]

Ross,
thanks for stepping in again.
Yes, changes to B3647 results in different AFRs. Through AutoVE I have enough evidence that it worked.
Since I use Semi-OL, maybe this has something to do with it.I don't know what the similarities between my case and the others are but the configuration must be somehow inhibiting the function of A0008.
Alex

[GMPX]

Well this makes no sense then, the A0008 table is referenced directly after the B3647 table value has been read, it's not like it can be skipped.
If possible can you put a crazy number in A0008? Maybe the scaling is off in the software display so instead of multiplying by 1.0 it's really 0.1, though I doubt it because it works for some people (including on my car if I recall, it was 4 years ago!).
If you were to set A0008 to the max value allowed you should see 'some' change to the commanded AFR/EQ.

Cheers,
Ross

[Alex99]

I would be happy to test waht you suggest, but right now I don't have the WBO2 installed. I could put it in the tailpipe though and check.
I'll have to wait until the weekend though - not enough time to play in between.
@ Brandon, maybe you can make this small experiment.
Alex

[smokeysbandit]

I'll see what I can do today!
-Brandon

[Alex99]

Here is an older cold start log with AFRs and my tune that I was running back then. You can clearly see the discrepancy between commanded and actual AFR.

[GMPX]

You can clearly see the discrepancy between commanded and actual AFR.
Yes but that can be caused by many reasons. I'll await the A0008 findings when you get a chance.

Cheers,
Ross

[Haans249]

How about another funny issue i've personally noticed..

This is also a different table: A0014

Its the IAT multiplier. It says to put anything above 1.00 to multiply the VE table upwards, but I've found that in colder temps, I have to put something BELOW 1.00 to increase fueling, and anything above 1.00 to REDUCE fueling (hotter IAT's). Has there been a fix for that? I'm running COSv5 OS# 02020005.

Thanks,
Adrian

[joecar]

Hi Adrian,

More info: showthread.php?t=2270 (http://forum.efilive.com/showthread.php?t=2270)

[Haans249]

Thanks, still not sure why its backwards? It must just be the way things are calculated.

[joecar]

I pm'd Tech Support about it being backwards.

[5.7ute]

Thanks, still not sure why its backwards? It must just be the way things are calculated.

It may not necessarily be backwards since the A0014 table is only as good as the data it recieves. Any variation between reported temp fron the iat sensor and actual air temp can have the table heading in the wrong direction once adjustments have been made.
Or like you say it could be ass about in the software.:doh2:

[Haans249]

It may not necessarily be backwards since the A0014 table is only as good as the data it recieves. Any variation between reported temp fron the iat sensor and actual air temp can have the table heading in the wrong direction once adjustments have been made.
Or like you say it could be ass about in the software.:doh2:

Well usually you're wanting to add more fuel when your IAT is lower than what your IAT's were when you set your VE table. For instance if you tuned at 70F IAT and have all your VE table values set at that temp, the IAT multiplier is to help you compensate for the difference in colder/hotter weather. So, with colder air, 30F IAT's you would want to ADD fuel, hence a value above 1.00, but in reality you have to input a value below 1.00 which according to the description of the table would be taking away fuel, leaning out. But it actually adds fuel.

[smokeysbandit]

Sorry I haven't logged anything guys, work has had me all over the country the last two weeks, and given the state of things, it would not be wise for me to turn them down. Hopefully this weekend I'll find myself in town and with time.
-Brandon

[joecar]

Brandon, take your time, no worries, we've all been busy too.

[GMPX]

Not sure why it would add fuel.
The value is a direct multiplication of the VE table numbers.
Lets assume your VE number is 1.000.
If your IAT table value was 1.010 then 1.000 x 1.010 = 1.010
If your IAT table value was 0.950 then 1.000 x 0.950 = 0.950
So given that the VE numbers end up lower I'm not sure how it could cause a rich condition.

Cheers,
Ross

[Haans249]

Not sure why it would add fuel.
The value is a direct multiplication of the VE table numbers.
Lets assume your VE number is 1.000.
If your IAT table value was 1.010 then 1.000 x 1.010 = 1.010
If your IAT table value was 0.950 then 1.000 x 0.950 = 0.950
So given that the VE numbers end up lower I'm not sure how it could cause a rich condition.

Cheers,
Ross

Well it does :doh2: haha. My IAT temp table starts with values below 1.00 and then moves to number above 1.00 in hotter IAT's. If its supposed to work the way you say, I should be starting with higher numbers to lower, but its just not the case. TAQuickness has found the same thing, and he was using the same OS I am.

Here is an example of my table:

LABELS IAT VE Multiplier (Factor)
IAT °F {link: SAE.IAT} Value
-40 0.991943
-22 0.994724
-4 0.995921
14 0.997118
32 0.998115
50 0.999113
68 1.000000
86 1.001307
104 1.002105
122 1.002903
140 1.003418
158 1.004150
176 1.004883
194 1.006348
212 1.007080
230 1.000000
248 1.000000
266 1.000000
284 1.000000

If I have a number above 1.00 in colder IAT's, it would lean out really bad. A number below 1.00 richens it up.

Best,
Adrian

[Alex99]

If you were to set A0008 to the max value allowed you should see 'some' change to the commanded AFR/EQ.

Hey guys,

after Brandon contacted me again on this issue, I have finally been able to do the above test.
A0008 seems to have a significant effect on the AFR after setting the values to 2.0 (max). Good news, I guess.
I guess I never tried to put in very high numbers because it didn't make sense.
The new question now is, why are the commanded values not matching with the actual WBO2 values.

I guess I can now start to modify A0008 to my needs, but it'll be mostly trial & error since the scaling is off.
When I did the test with max values, I got an AFR of 10.5 vs 14.6 commanded. It should have been closer to 7.5 (although it might not have run that rich).
After playing around with the table a bit I see a discrepancy of about 1 - 2 AFR points between commanded and actual, actual always being leaner than commanded.
Any thoughts on this new issue?

Brandon, thanks for following up,

Regards,
Alex

[joecar]

Make an A0008 ben map, filter out higher temps and throttle, and apply it to A0008 (very much like when doing AutoVE).

[Haans249]

Make an A0008 ben map, filter out higher temps and throttle, and apply it to A0008 (very much like when doing AutoVE).

I don't see how that would work, as that table adjusts the commanded fuel. On cold start up, you have to command a rich AFR to bring your AFR's down to 14.6. For instance, i have to command around 11.1-12.5 during my cold starts to get my afr's in line. If I were to use a ben map for the A0008, wouldn't it just continue to add more and more fuel? (commands 11.1 sees 14.1 - ben adds more, now command 9.0 sees 12.0 - ben adds more fuel etc...). I think you just have to play around with the table until your cold start idle gets in line, my table is as follows:

LABELS Open Loop ECT Commanded Fuel Multiplier (Factor)
ECT °F {link: SAE.ECT} Value
-40 1.020020
-22 1.020020
-4 1.020020
14 1.019531
32 1.014649
50 1.013184
68 1.010742
86 1.006348
104 1.000000
122 1.000000
140 1.000000
158 1.000000
176 1.000000
194 1.000000
212 1.000000
230 1.032227
248 1.084961
266 1.100586
284 1.100098

Not sure of the formula it uses to adjust the commanded fuel, but with the following table at start up of say 50F, it will be commanding 10.8 and sees 14.2-14.8, and as the motor warms up the commanding goes to normal and afr's stay relatively steady. Of course I'm sure that my VE vs IAT multiplier is also affecting the AFR's I'm seeing, but there is going to be a need for a combination of the two that will bring your AFR's in line.

[joecar]

Oh... make the ben map inverted... i.e. 1/ben.

[Haans249]

Oh... make the ben map inverted... i.e. 1/ben.

hmmm, have you tried this? I still don't think it'll work because you have to play with the numbers to get your AFR in target, there is no "correction factor" you can do to bring it in as the target AFR is not what is actually being commanded.

[joecar]

I played with it but I didn't succeed... my AFR diverges at cold startup, and slowly converges as warmup progresses.

[Haans249]

I played with it but I didn't succeed... my AFR diverges at cold startup, and slowly converges as warmup progresses.

Exactly as mine does as well as everyone else using COS in OL. Its interesting how the above A0008 table adjusts the commanded AFR. A 1.015 will command ~10.3, while 1 makes no adjustments. I can only imagine what 2.0 would command, and I'm not going to try hahaha.

[hquick]

I've had a little bit of luck playing with B3632 to try and combat the lean cold starts.