EO2K

iTrader: (37)

Wait, other than the 30-4100? AEM still lists it, and it has a serial output on the blue wire...

Wideband O2 Air/Fuel UEGO Gauge Kit



Am I missing something?

Braineack

iTrader: (62)

It's quite possibly a loose interptitation of the word serial.

Joe Perez

iTrader: (8)

(Slaps self on forehead.)

Yeah, I'm an idiot. And Brainey, he's completely right. This is standard RS-232. The manual even gives you the pinout for connecting it to a PC's serial port and using Hyperterm to capture the stream. I'm not sure how I forgot about that.

Seems as though the MS3 only accepts serial data from the Innovate, which is kind of interesting.

Ah, well. [/threadjack]

DaveC

Joe, what can you say about the accuracy of the wideband? Does it say exactly 14.7 at times when you know it should (for example)? Not that I'm sure I know when it should...

18psi

iTrader: (76)

we've beaten that stupid subject to death in another thread. do a quick search.
(basic rundown: innovate seems to respond fastest and give most accurate readings, aem much slower and does some sort of "averaging" bullshit that the geeks in here got their panties in a wad about because its not completely accurate to the .01......still works, and still good enough for 95% of the cars/builds here, just not "best")

please don't derail this thread (because I'm quite interested in joes "timing only" discussion and keeping variables to a minimum)

Next we can have a Fueling only discussion

After that we can have another wideband circle jerk

DaveC

I deserve that. This awesome thread is about timing not fueling.

I've had it in the back of my mind for a couple of days, and what I kept thinking was that if I (not Joe) was getting numbers that were consistently different from everyone else's, then I (not Joe) would wonder if there was something wrong with my results, not everyone else's. But I'm not Joe.

Anyway, never mind.

Joe Perez

iTrader: (8)

The question merits an answer, as it's relevant.

I have both the AEM sensor and the stock narrowband sensor connected to the MS.

With the MS's AFR target set at 15.3, and the engine idling in closed-loop mode, I observe the AEM's front-panel display to oscillate around roughly 14.7, and more importantly, I also observe the narrowband sensor to oscillate at roughly a 50% duty-cycle.

Thus, I deduce that (at least in the vicinity of stoich), the wideband sensor itself is working properly, and that the AEM gauge / controller is interpreting and displaying the sensor data correctly, but that the AEM's analog output is miscalibrated relative to what the manual says it should be producing.


This behavior is roughly consistent with what I remember from back when I was using this sensor with the eManage Ultimate, and later the MS1, on my last car. I replaced it with an LC-1 because of this, which is the reason I still had it lying around. (The LC-1 was sold along with the car.)

DaveC

Joe, thanks for the answer. That's pretty much what I imagined.

The truth is, you already showed that your timing numbers were probably real, which is where my aerated thoughts seemed to be stumbling before I got distracted by O2 sensors.

Sorry for crapping up your thread, and I meant no sarcasm when I said "I'm not Joe."

JasonC SBB

IIRC the AEM WBO2 uses a single ground wire for both power and signal.

It may be worth measuring the voltage between the ground pin in the back of the gauge, and at the MS sensor ground. A voltage difference here will generate an error in the measured voltage the MS sees.

Joe Perez

iTrader: (8)

Jason, thanks for the refresher course on DC Circuits 1. It's been a while since my freshman year of college.

The gauge is grounded directly to an ECU ground pin via a 4' long run of cable. If I'm developing 300mv across that length of wire, then something is seriously wrong.

I think we're done discussing this particular sensor.

JasonC SBB

I have seen IIRC 200 mV of error with an AEM UEGO, due to the voltage drop that the heater current develops in the long, single ground wire, plus the terminal pin connection resistance. The easy solution in that application was to shift the O2 sensor curve in the AEM ECU.

FWIW I noticed that the newer Innovate WB gauge also has a long single ground wire, with a voltage drop in it, but seems to have a built in voltage drop correction circuit because the voltage as measured at the ECU end of the wire, is correct. If you cut the harness shorter, the compensation will become wrong.

I have designed said voltage drop compensation circuits for cellphone chargers (which use a long thin cable).

hornetball

iTrader: (4)

Any more work on your timing map Joe? (i.e., trying to get back on topic)

EO2K

iTrader: (37)

+1. This is seriously the sexiest MS tuning thread I think I've read to date.

I wouldn't expect to see any updates until later this week though, if I'm not mistaken, I believe Joe has a commitment this weekend.

Joe Perez

iTrader: (8)

No updates, and sadly I also won't be making the 25 Hours race. I'm working on a monster project for WFAN right now, and will be heading off to NYC in a few days.

The spark map is "ok" at the moment. The car is running a lot better, and is obviously making a heck of a lot more torque all across the board. There's probably still room for improvement, I just haven't had any time to dedicate to it lately.

Joe Perez

iTrader: (8)

Been a while since I've posted here.

I haven't touched the ignition map since my last post. Been traveling a lot, and fairly happy with it in general. Good power, 30 MPG on the highway (original rating was 28), and 20 MPG in town, which is about what I'd expect from being Leadfoot Larry in a very hilly area.

Yesterday, out of the clear blue, the engine dedicated to start pinging all of a sudden. Any time I was on the throttle more than about 50% in the range of 1,500 to 4,000 RPM (I'm estimating here) I'd get a nice, sustained knock. Puzzling.

Hooked up the laptop for this morning's drive, dialed back the timing several degrees across the affected area, and did some logging / VEAutoTuning. For some reason, my fueling situation has gone somewhat lean. I haven't touched the engine, and the weather has been pretty unremarkable, so I have no idea what's going on (haven't tested fuel pressure yet.) But VEA was happily plugging in 15-20% increases in fuel all across the board. (My target AFR is 14.7:1 throughout most of the range, tapering into the high 12s at 100 kPa.)

For now, I'm going to work on re-scaling the VE table and then go back to my previous spark map. But take this as a cautionary tale: the spark tables I've been posting are clearly pretty close to the edge for 87 octane fuel in a stock B6 engine.

18psi

iTrader: (76)

I wouldn't be surprised if you damaged something, but as you said only time will tell.

I hope you keep updating this thread with updates, good or bad.

Did you ever do comp/leakdown on this bad boy?

hornetball

iTrader: (4)

I was wondering whether you were working on this anymore.

Your fuel tune being lean "all of a sudden" is wierd. Please post up what you find out.

inferno94

iTrader: (2)

As silly as it may sound, fuel filter?

I had something similar happen a couple years ago, I retuned but the lean-ness eventually came back (weeks later). I changed the fuel filter and the car became very rich, so I reloaded the original msq and all was good again.

Joe Perez

iTrader: (8)

I doubt it. After I dialed back the timing a few degrees and let VEA start to do its thing, the knock went away and the engine is still running smoothly and making good* power.

(* = good for a 23 year old 1.6 engine with poor compression)


I did a compression test a few years ago after I first bought the car. It was low and uneven- right at the bottom of the spec in the manual. Based on what I saw then, I'm kind of amazed that the engine is still running at all, much less returning 30 MPG highway and passing CA emissions tests with HC and CO numbers so low they barely register. I gotta hand it to Mazda; these engines aren't exactly power champions, but they're durable as hell.

If I can remember to do so, I shall perform another comp test. I wish I still had the original numbers from a few years ago, but they were written on the wall of my garage and I have since moved. (I've gotta stop writing important data on architecture.)


Nothing really surprises me with this car. 23 year old fuel pump, 23 year old FPR, probably a 23 year old fuel filter for all I know. The injectors themselves were cleaned and flow-tested by FIC last year, so I'm pretty sure they're not the culprit. It's not impossible that one of them has flaked out, I suppose.

With a fuel-system deficiency, however, I'd typically expect the engine to become more lean at higher RPM and higher load. But from what VEA is telling me, it pretty much just went lean across the board. So I'm just kinda puzzled here. Still, a new filter is probably in order, since I seriously doubt it's ever been changed in the past 210,000 miles. (Nothing else on the car exhibits evidence of having ever been properly maintained.)

Joe Perez

iTrader: (8)

So this is interesting:

1: 190
2: 185
3: 200
4: 195

This is on a "warm" engine, which sat for about an hour after I got home.

I could have sworn that when I checked this engine a couple of years ago, the compression numbers were completely for ****. Either these pistons are wrapped with magical rings made from unicorn horn and pixie dust, or my brain has the dumb.

I'm going with the magic rings theory.


Plugs:



The insulator on cylinder B is slightly whiter than the other three, but they all look pretty good to me.


On the fuel frontier:

Took my original fuel table (from before this morning's VEA run) and bumped it by 15%. Hand-tuned the idle cells back down a tad, then took the exceedingly long way home today while running VEA. Drove for about an hour, mostly back roads which allowed me to do a lot of up-and-down. Got home, and realized that the lapptop had gone to sleep after 15 minutes. (****.) But from what work VEA was able to do, it seems that the 15% boost was fairly close to what was needed.

Changed the power settings on the laptop, and will take the slightly-less-than-exceedingly long way into work tomorrow, and then the exceedingly long way home again. (It's a beautiful drive- through the twisty back roads of Elfin Forest and then out around Lake Hodges on Del Dios highway.)


Picked up a new fuel filter, but I'm going to wait until this weekend to install it, so that I have time for a nice before-and-after comparison with the pressure gauge.