Is it just me...

Or does most of this not look right? I included a quick scan of me pulling out into traffic and accelerating, My engine has a dead spot and I'm trying to get rid of it. I'm noticing that my 02 sensor is flipping out, I dont know if this is normal but the readings seem to be everywhere.

Experienced maf tuners want to tell me what should be number 1 priority with this mess? thanks

Also I set my "Max timing" to 35° and im getting advance well beyond that.

 

First thing I notice is wow, lots of knock counts. How many do you get at startup? I usually see about 10-21 counts from starting the car, and very few from driving.

What I would try to do is play with the injector pw vs battery voltage correction in the 12.8 to 14.4 range to fix the rich idle.

Maybe try to get some decelleration data saved as well, get into some different cells?

 

Actually maybe you could help on another question...

Knock was main concern at first thinking thats what was robbing my power. I noticed not alot of counts persay, but a lot of retarding.

What basis does the ecm choose its amount of ° of retard on?

 

I'm not exactly sure. The memcal does some filtering on-board, and passes some kind of value to the ECM. I've noticed that I get some retard without the knock counts increasing. It's always a small value though, usually less than 1.

Are you burning chips or just scanning? I zero'd the entries in the PE mode spark advance array, and that helped a lot for WOT operation.

 

I tune and scan...

And so many things dont add up

Like my 02, its high, its low, its high.

Them my knock, i retarded as much as 7 degree's on one count

Is it how BAD it knocks? or is a knock a knock?

Then there's the max timing, which was 35, and I have recorded advance as high as 47 I believe it was.

 

I havnt downlaoded it yet (at work) but isnt the o2 sensor supposed to ping pong back and forth by nature?

 

What mask are you using? $6E? What exactly do you mean by you have the max timing set to 35* . Like in WOT or throughout the entire main spark table? Have you zero'd out the WOT spark adder?

I am not an expert on the ECMs handling of knock either, but I remember Glenn talking about it and he was saying that the way it deals with knock is that it constantly 'listens' for knock. When knock occurs - no matter how "bad" - it pulls timing out. It continues to listen and if it still hears knock, it pulls more timing out. The system will continue to do this until it hits the max timing retard parameter that is set in the PROM or the knock goes away. So if you are seeing lots O retard with little knock it is likely due to the max timing retard figure being fairly high.

Now you can certainly lower that figure to get less retard, but I would strongly suggest not doing that until you are comfortable with the amount of timing you are running. If your engine really is experiencing that much knock, the retard is saving your engine for you. But backing down the timing until you get either no knock or are so ridiculously low on the spark that the knock really must be false is a much safer plan of action. If the knock ends up being false, you can investigate from there.... But every engine is a bit different in its timing wants and more timing doesn't necessarily = more power.

HTH,
Matt

 

Yes $6E

Why Zero out WOT spark adder?

As far as I know WOT is working great, its part throttle or 70% throttle area's its got a dead spot and I can't find it on the scans, other than the unsteady A/F ratio

 

Sorry bout that, yeah, the WOT adder shouldn't be the problem if the knock is happening at part throttle. brainfart.....

But the areas that you are seeing all of the timing (like over 35*) are in the part throttle stuff where the timing should be higher than the WOT stuff. Assuming you are using an ARAP as a base, how much of the timing table have you played with? If you didn't mess with the part throttle areas, the timing you are getting is normal for ARAP.

I hadn't looked at your log for the other post, but seeing it now, I don't think you are seeing anything different than a lot of us ARAP users have/are seeing. And that is that the part throttle timing is VERY aggressive and may need to be backed off a bit to avoid knock. Massage that main timing table (keeping track of where you took timing out and how much of course) and see what that does.

Oh, and your O2 seems fine. It is cycling back and forth as designed. I'm not sure if you really were asking about that or not, but it is supposed to go rich-lean-rich-lean and so on. That is it's job. And CMs program calcs AFR from the factory O2, so......... No sense in using those AFR figures.

 

So if such a wide band of 02 cycling is "normal" how does the ecm even know where to begin with fuel. I'd expect the BLM's to be just as wacko but they seem to disagree with the actual voltage output of the 02 sensor


Can you see anything in the data that would hint towards my dead spot just short of 2k rpms?

Is it timing? and with such crazy 02 readings how would you begin to know it was fuel related?

 

The ECM knows where to begin with fuel by using the injector constants and the MAF signal (along with a few other things here and there, but those are the two main ones) to deliver the correct amount of fuel. The MAF will tell the engine x amount of air is coming and the ECM will use the Injector constant that is provided by the PROM and apply the correct amount of pulse width to the injectors to get the engine to run where it thinks the correct AFR should be. In open loop the ECM runs on preset routines and in closed loop it uses tendancies of the engine in the rich or lean direction to trim the fuel. In CL it basically looks at how often it is rich or lean and attempts to shoot the gap and get it as close to the middle as possible. It does this by watching the O2 over time which is characterized by the BLM and the INT. I would go on, but this has all been discussed over and over and by better men (maybe women) than me, so do a search on BLMs and read up on them.

But basically you are scratching the surface of why everyone wants a Wide Band O2 sensor (for WOT at the very least).... The factory switching type O2 (like yours) is not capable of reading Air Fuel Ratios like a Wide Band is. The switching O2 knows three things: Rich, Stoich, and Lean. That's it. Now that works fine if it is able to watch the O2 output over a length of time and make changes to the fuel trim to get the O2 to bounce as 'close' to stoich as possible, but at WOT, you go through the entire RPM range at such a furious pace that the ECM is unable to make a determination about what is going on and apply what it determines and make the difference it would intend. Now A wide Band can isolate individual Air Fuel Ratios throughout the ratio range. This ability comes with a price tag of course....... And you still need to know how to get the AFR to change with the given tools you have......

HTH and Good Luck ,
Matt

 

So how come there's only the MAF calibration tables, and not a mav vs pulse width table? Or is there and it just isnt' availiable in winbin or hasn't been hacked?


MAF seems more and more useless the more I look at it

 

The pulse width is determined by some additional factors, like RPM, load, coolant temp, etc. Although I think there must be some additional stuff we don't see in WinBin, because there should be a way to tweak the way the different cells are treated.

I'm running about 135 at idle, 7 gr/sec, cell 0.
I'm running about 120 at decel, 7gr/sec, cell 2.

Seems like there should be a way to fix this, but we don't have enough information.

Join the club.

Have a look at the '165 Guys Unite' post, it should be near the top.

 

MAF would be alot less suck if we could get our hands on that stuff


The A/F tunability of MAF seems to be virtually nill, considering that the only ways you CAN adjust it is just pulling one string to effect the other.

Pulse width VS LV8 tables and things like that would be endlessly usefull