Spark advance drops off to 3 while trying to idle

[Tracyrr]

I'm just starting on my idle tuning and noticed one thing right away while logging....my spark went from 25 to 3 and then died and i also noticed that my map is really high. The cam is 238/244 at .050 cut on 116. I'm going to continue reading the idle threads that joe provided me but this one should be pretty easy i would imagine. The log and tune is attached and the issue was at frame 7203. Thanks for any help guys, tracy

Log_0036.efi

geoff original.tun

[SOMhaveit]

I.m guessing you have a vacuum leak somewhere. 73kPa at idle is way too high for your cam. You should be in the vicinity of 45 to 50kPa. My G5x3 idles at 50-55 kPa. In addition, something is amiss with your TPS. You are reading over 15% at idle. If it's fly by wire, I see 8-12%, the higher # being when the A/C is on. Under system properties, you are a Y-Body, yet your injector flow rate is set for a single value like you have a fuel supply system that operates off a vacuum actuator and circulates fuel back to the fuel tank(S).

[Tracyrr]

oh yes, it is a custom twin deatschwerks 300+ pump system with return. The car is a twin turbo C5 corvette with a 408". I have been reading and working on the idle today and have made some progress. The timing was dropping because the desired idle was 300rpm's off so it killed the timing (auto tune). I am reading and re-reading on how to run a calc-ve so i can map my 400 - 1200 rpm cells. It is a fly by wire throttle body. It idles much better with the a/c off although i never run without the a/c.... Thanks

[joecar]

Try logging the EST_xxxx_DMA pids to see if they indicate where/why spark is being pulled.

Also log the STATE pid that shows A/C request/status.

[DrkPhx]

Humor me and try adding spark (same as base spark in gear) in the lower range of the Minimum Spark Advance Table.

[Tracyrr]

I got it worked out pretty well. I basically followed the idle tips and it improved the idle greatly. No more dying!! BTW DrkPhx, i did add advance to the base spark and that improved things as well. Thanks guys

[joecar]

Hi Tracy, can you post before and after .tun files, thanks.

[Tracyrr]

Sure, but no laughing....lol From a 1 - 10 scale, my idle went from a 1 (didn't idle at all) to a 6 (idles descent but could use some work). If you happen to see anything obvious that i need to address, just let me know. Thanks joe for the help!

geoff original.tunBefore

geoff original.tunAfter

[joecar]

We don't laugh at people

Hmmm, there are many changes between those two files...



BTW:
if you do File->Save As, the filename will have an incrementing number appended to it, so each time you do File->Save As the filename will increment...
so you would get filenames in this sequence:
geoff original_0001.tun
geoff original_0002.tun
geoff original_0003.tun
. . .

[Tracyrr]

Oh yes, i was working on WOT for most of the changes. I also had a bunch of trial and error on the idle tune, lol. I will keep my day job!