help a NOOB. weird timing

[schardbody]

its a 04 colorado. recently went to an 87 octane tune, then today back to my 93 octane tune, and made a quick drive as always just to make sure everything is good to go. well, everything felt fine but i noticed some spark knock on the scanner. so i take a look at the commanded timing in that cell and the actual timing. commanded is something like 19 degrees, scanner shows -8 degrees, it happens in a few cells, and these are most of the cells im showing knock.

anybody have a clue whats causing this, i've never noticed it before. heres my tune and LOG. its a 2.22 file so anyone with the beta probably cant view it. thanks in advance.

Attachment 18854

Attachment 18855

[schardbody]

no help???

[HawkZ28]

Didn't have any problem w/ opening w/ beta.

Your IAT's were high in the beginning- that can help lead to KR. Also, zero out the burst knock tables- all we can read on ours is KR- BK will read as KR as well IIRC.

From what I've seen and read on our I5, we tend to get KR in some really weird areas- it seemed like yours (majority) was during transition from light to moderate load, as well as lift off/decel in some cases- pretty common to get it in the decel cells it seems w/ the I5.

If we had access to some transient settings, I think it would help- my guess is it's a momentary lean condition tripping KR IF it's real KR and not false. You could run a tank of HO if you aren't already to see if it gets any better (real), or desensitize the knock sensor.

Just my $.02.

[schardbody]

thanks for the input but honestly i know about the KR, what im trying to figure out is why im not getting the commanded timing??? i thought my BK tables were zero'd thanks for letting me know about that. thats one of the first things i do.

and the knock sensors cant pull 30 degrees of timing which is whats happening, which is most likely the cause of the KR. the KR is pulling the max.

you are right its mostly on quick starts.

i could care less that there is KR, what i want to know is what is causing the PCM to drop 30 degrees of timing or whatever in those cells?

[HawkZ28]

My bad, I was trying to feed our daughter and post, so I read -8 and knock .

Which frames was it in?

My guess is it has to do w/ the IAT Spark base and mult in conjuction w/ the coastdown table? Also, if it's happening when in decel/when you are hitting DFCO, the computer will ramp the spark down to 0*.

[schardbody]

i guess we are pretty much on our own with the colorados.

hell im getting knock retard at idle, nuetral revs, and decel. there really isnt much knock on accel. cruising at a steady rpm and TPS i get knock retard. its annoying the hell out of me. im almost sure its false knock.

my main concern is the -8 degrees of timing when it should be 28 degrees in that cell.

[HawkZ28]

You are probably right. Makes us better, though!

I will get an issue every now and then at idle- only when cold and just started- where the engine will lope and fluctuate from -3* to 8*, for about 15 seconds and no reason, and then just disappears.

Seriously try desensitizing your knock sensor. Directions are here.....http://www.hptuners.com/forum/showth...d+attack+decay

Just be sure you eliminated burst knock first. Also, if you drain the tank down and run a tank of HO, and it disappears, you know that it's real KR.

Maybe if you back off your base timing by 2*, or decrease your HO by 2 that might help too. See if it helps, and wash and rinse a few times if it does til it eliminates it maybe? IIRC, the PCM will add to the base a number of * between the LO and HO table. I wouldn't quote me on that though.

[schardbody]

what do you mean base timing??? all i have is hi and LO octane tables.

i changed some things, going to take a ride later on. the tune i attached up top isnt even the right one, but the LOG is.

you still keep going back to the KR, again, i dont care about the retard, i know how to get rid of knock retard, just cant figure out what is pulling 30* of timing out of my tune?

[HawkZ28]

My bad- I promise, no KR reference this time around.

Try looking at your base tables for Idle spark advance, over/underspeed, IAT, ECT, etc....I have a feeling it may have something to do with one of those.

You are running the 2006 tune on an 04/05 correct? Did you catch that the parameters for the Cat Lightoff Table were completely different between 05 and 06? That could be a cause, too (?). One is ECT vs Airmass, the other is RPM vs Airmass.

At least some ideas to look. You are positive all your TM is disabled, too right? Just trying cover bases.

[schardbody]

TM is completely gone. cat lightoff is just at warmup, i dont make any logs until operating temp is achieved.

thats the wrong tune. the tune i am using is 06 based, but VE, MAF, and PE has all been tuned. of coarse trans, speedo and other things have been changed.

i'll post my tune now.

[schardbody]

[HawkZ28]

When it happens is it always during a hard throttle transition, during moderate accel, just cruising, etc?

Just a couple quick suggestions....

Engine/TM/Tract Control/Enable temp- set to 493 to be sure it's not kicking in.

Engine/Spark Contr/Burst KR/ALL- Zero out. These could be pulling timing, and will just show up as a change in commanded spark IIRC for our trucks.

Hopefully one of those will help. Otherwise, I'm stumped.

[schardbody]

you realize that the burst knock table is a predetermined amount of timing to be pulled on big transitions. mine is set to 2 degrees. thats not going to cause 28 degrees of timing difference between commanded and actual timing.

the other table i dont even see, or im not reading it right. i dont have any temp. tables for torque management, nor anything with traction control in it. maybe thats the table i have disabled altogether is why i dont see it.

i thin it was just a false reading, i am plotting alot of pids, i guess i just need to redrive it, i made the changes to the knock sensors according to RussK's post, although i dont see how that de-sensitizes the knock sensors, if anything it looks like it will just give them less control of retard, but i'll try it anyways.

i'll let you know what happens, thanks for the input.

[HawkZ28]

I know that, but at least you eliminate that as part of it- then you're only chasing 26*....I wonder if it's a combo of things- either some parameters we have no control over w/ the I5, or something we're both missing.

Even looking at your spark tables, I don't see how it could be that much- there's not that kind of difference between your LO and HO in the same cells to blame it on adaptive timing.

[schardbody]

the difference between my hi and low tables is ALWAYS 15%. i set both tables to the same base which is usually 2-3 degrees advance. then tune the hi table. once its all set i just copy it to the lo table and multiply by .85.

i get what you are saying about eliminating the BK now, just to rule it out. eventually i'll make another log and see if it does it again. i doubt it does it again, think it was just one of those things.

i also thinks theres TONS of parameters we dont have access to. i'd really like to find a table that effects throttle speed, the larger the transition in TPS the SLOWER the throttle opens, thats annoying.

[HawkZ28]

i also thinks theres TONS of parameters we dont have access to. i'd really like to find a table that effects throttle speed, the larger the transition in TPS the SLOWER the throttle opens, thats annoying.

X2 to the 21342346234524524352435 power.

Just gotta keep telling ourselves it's the 'good fight'.