PE Timing adder? Commanded advance differs from actual

[Supercharged111]

I could swear that PE mode adds timing, but I can't find it anywhere. I have found B5908, Fuel Mixture Spark Correction, but I don't understand its function. WOT 4400 RPM's 85kpa and 22 degrees of advance according to the main timing table. ECT and IAT's were in check so they weren't screwing with my timing, I had 1.88 degrees being pulled but the Scanner still indicated 23.5 degrees of advance being present. My altitude sucks apparently. With a full airbox I drop to 85kpa (from 88) by 3700 RPM's and with air filter and airbox lid removed I don't hit 85kpa until 4900 RPM's, is that 1-2 kpa being lost over the RPM band significant? And what am I missing? Why is more timing being added?

[Supercharged111]

Alright I got impatient and copy/pasted this B5908 to an excel document and zeroed the thing out in the tune. Then I guesstimated a WOT timing curve and went out for a test drive. No more KR! Sweet. It even pulled a little better due to additional timing, but it was still 5 degrees shy of my main advance table from 4000+ and 2-3 lower below 4000 at 85kpa with no KR detected. What gives? My ECT was around 94C and the table doesn't pull timing until 98C. Even then it only pulls 1 degree, so it'd probably interpolate between the 2 and pull a fraction of a degree of timing. IAT's were in check, is there some torque management that I forgot about? The only torque management that I'm aware of right now is the upshift. I disabled absue mode by setting D1019 to 0.0kmh. I'm really at a loss here, this PCM is pretty bare bones so as far as I can see there aren't that many modifiers.

[joecar]

Which PCM/vehicle/year/model...?

Post your tune/log files, someone may have an answer.

[Supercharged111]

Vehicle should be in my sig now, a 1998 GMC Sierra K1500 5.7/4L60E w/stock PCM. My elevation is 3200ft and I was running 87 octane. I've attached a quick 1-2 pull on 87 octane, and a larger log on 91 octane. I found last night that my PID's got screwed up somehow and the correct knock retard PID was swapped for the wrong one. I sure as hell didn't change them, I don't know why it and the commanded AFR PID's were both changed. At any rate, the most KR I log is 4 degrees, yet somehow it always manages to pull more than that. How is this possible? What is pulling the extra timing? The abuse mode I disabled? Or how about the TM that's only supposed to intrude on my upshifts? Did I miss some other TM somewhere else? Or is there a KR multiplier somewhere? Even if there was, it should tell me it's pulling 6 degrees and not lying to me telling me it's only pulling 3-4 when I'm losing 6 degrees or more. I tried retarding the timing to stay out of the detonation, but it still pulls it and I end up with way less timing and the truck falls on its face. I don't know what else to do. . . just crank up the timing so the end timing is what I want?

Edit: Forgot to upload tune.

[Supercharged111]

Right here my timing gets ganked to 11 degrees. I'm unaware of any TM on my downshifts and the main timing table calls for a good bit more than this. I must be missing something huge. I should also mention that a 180 stat is in my very near future.

[WeathermanShawn]

Was your IAT was really 54C at the time?

Your Spark IAT Table was pulling out 2-3 degrees of timing?

[GAMEOVER]

Thats kinda warm....

[GAMEOVER]

How much timing did you add? Post up your stock tune...

[Supercharged111]

Dammit, stupid IAT's. You're right, there's a couple degrees on the WOT for sure. But that still doesn't account for the rest of the lost timing on the screenshot: I'm losing like 6-7 degrees with no knock retard. 2-3 can be chalked up to IAT's (need to reinstall airbox lid) but I'm starting to think the rest are some TM that I didn't successfully disable. And why in God's name will this thing not take what, like 26 degrees of advance?! What a crock! Here's the stock tune for your viewing pleasure, please note that my tune has B5908 0'd out and the rest added into the main table. When I logged mapped RPM vs TPS for knock (in an effort to see if high loads outside of PE mode would induce detonation) I found most of my knock to be in the WOT and some in the cruising RPM/load cells encountered in OD at 70mph so thus far zeroing that table appears to be a success to me.

[Supercharged111]

Just for a quick visual, it looks like my values hover around the stock values very closely, but I choose to ramp up the timing more slowly and give more in the end instead of taking it away as RPM's climb. Unlike the stock tune, which has the most advance at peak torque (?!) mine is milder at peak torque and advances after peak torque. Below are the values of the stock tune and my current tune at 85kpa:

85kpa 2400 2800 3200 3600 4000 4400 4800 5200
stock 23+2 25+3 25+3 24+3 21+3 20+4 20+4 20+3
mine 24 24 25 25 26 26 26 26

I should also mention that I don't have problems until after peak torque is achieved. I really need to hook up the wideband to make sure commanded AFR's are what they claim to be, but they can't be that far off right? Engine's bone stock, stock exhaust, stock paper air filter!

[hquick]

As soon as I get a warm day....I get KR. I have seen IAT's as high as 100oC before and it pulls ALOT of timing
Regular driving is always around 50oC or so. I NEED to install my intercooler!

[Supercharged111]

So does anyone know why this stupid truck won't take any advance?

[WeathermanShawn]

There are multiple Spark PIDS modifiers you can log.

1). Real Knock. Usually only pulls 4 degrees when in PE Mode.

2.) Burst knock..It will pull timing. You can zero it out.

3). Traction control. You are going to 100% throttle pretty quick, but I see a lag in your vehicle speed. Are you disabling any ABS/Traction Control etc? That will pull spark.

4). Anything ridiculous like your AC on? It should disable with WOT, but it can pull spark due to the AC compressor kicking on.

Your IAT was 133F temp and you ad 3 degrees of timing being. Either Traction Control, or Abuse Management is not configured properly.

[Supercharged111]

Burst knock retard, I just googled it and disabled it. My only options were the lo/hi MAP values to enable it. Hopefully, with this ECU's lack of AE that won't be an issue, but we'll see. . . I really hope someone can chime in and at least tell me if Abuse mode and all that other garbage has been disabled. The only mention of traction control that is in this PCM is the minimum advance when it's active, but no other parameters. This PCM is gay, it's like only half of the crap on there can be changed. I left some TM on the upshifts, but as far as I can see that should be it. So do I just need to accept the fact that this will pull 4 degrees in PE mode and command a few extra to make sure I get what I want in the end?

[Supercharged111]

Come on guys, I'm begging you. I know someone knows, check this out: IAT's are around freezing, coolant 194 (180 stat will be in on Sat), what TM do I still have active to steal 2.5 degrees of timing? Later on in the log it steals a mysterious 3.5 at an RPM nowhere near the shift point. This is absolutely slaughtering my truck, I've searched my ass off and can't find what I'm after. I've even attached my tune again which seems to change about 5 times a day.

[hquick]

Don't know if it's just me but when I open your log and tune together I get a VIN mismatch message which makes it difficult to track the source of lost timing.
Tune says auto, scan says manual???

[Supercharged111]

I've always gotten that VIN mismatch as well, don't know how to fix it. I'm afraid if I start changing VIN's around I'll waste my licenses.

[WeathermanShawn]

At this point it is apparent you are getting some legitimate knock, along with your mysterious loss of timing.

It always helps to have all of the basics and modifications of your vehicle in your signature. Is it an auto? Your tune says manual. Are you supercharged? Your user name says yes, your tune says no.

When you get to the point of changing your tune multiple times and "you do no not how it is changing", it is probably best to just reload the correct stock tune and start over. I would just re-organize your tune, logs, and clarify what vehicle and tune you are using. If you I recall you are using 87 octane gas. Why not 91? Do you have a wideband?

It is just possible that you are running quite lean and with lower octane gas the timing being pulled is legitimate knock.

[joecar]

I've always gotten that VIN mismatch as well, don't know how to fix it. I'm afraid if I start changing VIN's around I'll waste my licenses.A License attaches to a PCM or ECM/TCM regardless of VIN, so you won't use up another license if you change the VIN.

[joecar]

Have you tried logging the pids whose names start with EST_ (I don't know if they are supported by your PCM or not)... these will show where/why timing is being pulled.

[joecar]

TM only pulls timing during a gear shift.

[Supercharged111]

Looks like a big, fat negative. I'm gonna log the stock O2's and see what my WOT voltages are, that'll at least tell me if I'm way lean. I don't think plugging in the wideband behind the cats would work very well.

[Supercharged111]

Just to clarify the truck in my sig is the one being tuned and it's bone stock. I'm running 91 octane and due to the stock exhaust, no wideband yet. Once I transfer the header back from my '88, I'll have another bung welded into that one for the wideband. I tried tuning VE last night based on the LTFT, but that didn't work at all so I put the VE back to stock. Honestly, I haven't screwed with a whole lot. I've disabled the EGR system, rear O2's, and their associated MIL's. I shortened the shift times, tweaked OD shift points, and reduced/resloped TM. The main timing table is where I've spent the majority of my time and now I feel it's getting to the point that I really need to do the VE table. I also realized the other day that I need to go over basic tune up items, as the fuel filter I just replaced was pretty plugged (and made NO difference in performance once I replaced it, bunch of crap!). I only bought the truck a few weeks ago so I'm still finding things out about it. If the stock O2's, as inaccurate as they will be at WOT, indicate what appears to be a sufficient amount of fuel on the top end, then I'll be at my wits end. Tell me if I'm crazy for thinking that on 91 octane at 85kpa and a commanded WOT AFR of 12.3 that this thing should take 28 degrees of advance? Even 26 would be a kick in the ass over what it's taking right now.

[WeathermanShawn]

The only thing I see in your tune that would be pulling that much timing would be if your Traction Control is active (B1003).

If it is not off, it will pull timing/torque as described in Table B7970. I.E., if you are spinning your tires, it will drop lots of spark/torque. You could always play around with Table B1027, Minimum Spark Advance and set those limits a lot higher. Or perhaps set Table B5908 back to stock.

If your vehicle is in sound mechanical condition, no vacuum leaks, and a stock CR, don't see why you can't take 26 degrees of timing.

[Supercharged111]

How can I disable traction control? Or did I already do so by unplugging the ABS pump? There is no enable/disable button when B1003 is selected, only minimum advance which I set to the 105kpa values for now, unless there's a better answer? I don't want to touch B7970 as I'm assuming the TM for my upshifts references this table as well? I copied/pasted my main timing table into B1027 and was going to have it 5 degrees retarded from the main across the board, but then I remembered I've left some upshift TM on the table, so I ganked 18 across the board for now. At least the curve matches the main table, all I have to do is ctrl-A and increase them to whatever I want at a later date. B5908 is zeroed out, I'm doing it all via the main table. I tried pulling some from the main and setting B5908 back to stock but I still got the knock, so for now I'm working solely off of the main table. I thought I might encounter knock in OD when the motor sees 85kpa in closed loop by doing it this way, but the only knock I get is from just after peak torque on up and only at WOT. I also logged knock retard based upon RPM and throttle position and the only time I get it is WOT. That's what got me thinking there must be some TM/TR still intact, but neither of those will show up in the KR logs, only in my spark advance logs. I suppose if the stock VE map is as crappy as the stock timing map was, that could be where my problem lies as well. From my searches, I'm seeing that the MAF could be causing this, can I simply unplug the MAF and go for a drive in SD or is it more complicated than that?