RomRaider

I have been noticing an almost 10-12 degree drop in total ignition timing with no signs of FBKC or FLKC. It happens during both acceleration and constant throttle/load. My advance timing table is 10 degrees across the board. I wonder if it is just a communication issue? I am getting almost 4 sample per second, but timing is the only "data" that goes funny. below are three seperate bits of the last log. oh, and the AFR's are good as well

edit: why can't I post the code...hold on

There's different timing behavior that ramps in and out of idle. There are also other timing compensations that are not knock related. Try logging the idle switch as well.

to clarify, there are three seperate sections above...and it does not happen during idle, or coming in and out of idle, that I have seen yet. I'll try the idle switch log.

so many "other factors" to consider. do other EM systems have all of these little quirks. why can't timing just be timing

What I'm saying is that it may ramp timing up upon leaving idle over short period (and the period determines the ramping behavior). I haven't messed with it much, but it appears if base timing is greater than idle base timing (which is not currently defined in the defs) this ramping will occur. It should be very quick. Try logging the idle switch as well as base timing.

if it is ramping up as you say, why would it be doing it if the timing is already ramped up? IT is dropping 10-12 degrees for one line in the log and then back to where it should be...

I have also been seeing negative timing values, mostly when going from idle to something, or going into idle. it does funny things when the clutch is "slipping" in and out.

well, it could be due to one of the other timing compensations, but I would log base timing, timing advance and the idle switch anyway (along with FBKC, FLKC, RPM, load, total timing, TPS). That will rule out the idle timing and something funky with your base or advance maps. If that shows nothing, then I can send you some custom logger defs to see which of the other timing compensations are coming into play (not all are defined in the defs). These other factors would not appear when logging base or advance, only total timing.

I may have an older set of defs, but I do not have an "idle switch" per say. I have an "idle speed target map selection" and "ISCV duty ratio" I went back and looked at older logs and found the same thing. it also happens during decelerating and shortly after large throttle inputs, or whatever results in positive quick load changes. however, the high timing values have already started the ramp up, then it drops for one line, and then falls right back in line with the correct values. I don't feel it in the butt dyno, but it would be nice to know if it is seeing something that needs to be corrected.

I'll try the defs if you like.

you have to look under the switches for the idle switch, not the other logging parameters (in the box below). Log what I listed in the prior post, post it up and we can go from there.

Merch,

here is the file. the "points of interest" are all over the map.

Wheeler

That log tells us nothing. You need to log base timing and timing advance as I suggested, not just total timing. If base timing and timing advance are normal (as per maps) and total timing drops (as in your problem), then it is a timing compensation coming into play. You can't determine that otherwise.

Also, post up the raw .csv file in future logs. So, log the following:
base timing
timing advance
idle switch
FBKC
FLKC
RPM
load
total timing
TPS
IAM

- I looked at my other timing comp tables, but I do not think that they are coming into play, unless I have a sensor that is going whack. I'll log coolant temp as well, but the maximum compensation is 4 degrees. My intake temp sensor shows no issues.

here you go.

Looking at time 224110, you can see that the drop in timing is caused by one of the timing compensations. Not all of them are defined in the defs because they haven't all been worked out. However, I have a general idea of what they do. I can send you a custom logger defs to figure out which one is coming into play. What is your rom id (A4SGE01C)?

do you think it is the same case for time stamps


and yes, my rom ID is A4SGE01C

any idea why the compensation would only be on one line, or what amounts to basically less than a 1/4 second?

if base timing + (advance*iam/16) + FLKC + FBKC is less than total timing, then one of the other timing compensations is coming into play. Why it would only last a split second just depends on which one of the unknowns it is - they are not all as straight forward as the ECT and IAT tables. I'll PM you some custom logger defs today or tomorrow.