Guys/ Gals,

Thought there might be some people interested in my results from tuning the ignition timing for a better idle. Please see the attached file.

Let me know if this was helpful or not.

Merry Christmas!

HiVolt EVO8

 

Well,

I have been running around with the map changes expressed above. The car throws PO300 codes now...........but I can deal with that right now. The one thing that I cannot deal with is a slight "stuttering" that appears every once in awhile. The funny thing is that this stuttering appears when the car is operating in a part of the map that does not have advance in it. If I lift the throttle and reapply it, the stuttering goes away. This is definately an ignition related issue.

It seems that the ECU does not like advancing the timing. I am not sure if this is a CAS replication issue or what. However, I cannot determine why this issue would arise only in advanced timing situations. I also realize that advancing the timing is predictive algorythms in lieu of replication algorythms.

I am really interested in Shiv's comments regarding this. If I cannot resolve this issue, I feel that I may proceed with a different form of engine management. I do not like AEM due to their injector drivers. I am strongly considering the Power FC route.

 

Have you tried reducing the area that has advanced timing? For example make it zero out by 1300 rpm and up to only 18% load? I have 272's and it only idles rough when its below 1000 rpm.

I have also experienced that stutter when I tried advancing timing in low load cells.

 

Rushin,

Thanks for the assistance. I will give that a try and see if it will reduce or eliminate the stuttering problem.


HiVoltEVO8

 

That's an interesting experiment you're doing. Has anyone else tried this successfully?

 

Not that I know of. However, I am sure that this is what has been done with the idle flash for camshafts. I am just trying to use XEDE to do the same thing. Hopefully, this works.

 

I tried to adjust the timing earlier today. I set it to +5 in only 4 cells - loads 2-10 and 500-1000 rpms.. seems to work ok with no po300. The idle is even but still rough. Not bad

 

+5 degrees is about the breaking point that started to make a difference on mine. The closer I got to 9, the more vacuum and better idle was produced. I have implemented your recommendations, but I have not driven the car enough to know if the PO300 issue will pop back up. Only time will tell

 

yeah this is interesting! keep us posted!

 

Well Guys,

I changed the mapping to where the advance tapered of quickly to 1500 RPM. I still get the PO300 CEL. I am going to try just 4 cells this time like Rushin.

 

I tried just advancing the timing in the 4 cells that the car operates in at idle. Unfortunately, the car still is throwing the PO300 codes. This is beginning to seem like a lost cause. Let me rephrase it, my car is running the best that it ever has at idle. I have GSC 272 cams, Cam gears set at -3/-3, constant 800-850 RPM idle, and 15" Hg vacuum. The only issue is that it is throwing the PO300 codes.

I am going to try an experiment with my OBDII scanner and leave it installed in the car during driving to see if it eliminates the issue. Just a hunch since the SMART system incorporates a C-reader, which should do the same thing.

I will post back here when I have results.

 

Nice.. hopefully you can get rid of that annoying po300. As for me I like the lopey idle