New to logging, need advice

[TurboTerror99]

I've read through a lot of threads and information and feel like I need to discuss it with someone directly relating to my car. I recently got a Palm IIIc with the MMCd 1.8 program. I've logged a few test logs trying to feel it out and get a good understanding of how to work and read the logger. My symptoms are I'm running pig rich and doesn't run properly. After logging some I pulled a coolant temp sensor code. I've fixed my boost leaks and it's still running rich. Could the temp sensor be keeping the car in cold mode and causing it to run rich? It's reading 80-81degrees after driving it for 15 minutes. Also, I logged 18 counts of knock on my way to work this morning and I wasn't boosting it up or anything. Could this be because of the extremely rich conditions? O2 is reading2.5v. The Fuel trim is staying at 100%. Lastly, when I boosted it up the other day at around 5500 rpms the INJD was at 90.6%. Should that number be lower but isn't because it's over-fueling? I know it's a lot of info but even if you know a little bit I'd appreciate the advice. Thanks in advance!

 

[SrKegler]

Replace the coolant temp sensor (2 wires on it) then log it again. The knock counts could have been from rich knock.

 

[TurboTerror99]

Thanks, SrKegler. Is the 2 wire the one in the thermostat housing and controls the computer... not the gauge?

 

[We're on Boost]

Here is a log from when I had a 3" downpipe, test pipe and exhaust. I still had stock injectors, stock fuel pump, stock fuel regulator, stock ecu, stock 1g MAS. I was logging with the ecu+ which at the time had the fuel map and ignition timing maps all set to 0 (stock). I figure this setup was about like what you have now.

The pic shows a WOT pull. The cursor is positioned just after I started to lift (TPS). Notice the injector duty cycle (where the mouse is) is 95%. The O2 voltage here is only 0.69 volts - that's low, so I'm running pretty lean here. In fact, the next thing I did after coming back from this run was to add some fuel in the fuel map high load range. Then the next time I went out for a pull (not shown here), with the increased fuel, the MAS Hz went over 2000 and I got my first fuel cut. Your duty cycle of 90% sounds about right.

In the Knock Sum window you can see I was getting some knock, about 6 counts where the cursor is, then right after the next spike in knock sensor voltage the knock sum went up to 9. This is cool, being able to see how the actual knock sensor voltage relates to "knock sum" which is reported by the ecu. Anyway, with the knock starting and the low O2 voltage I knew I needed a richer AFR up there. I didn't have a wideband yet.

Other things worth noticing: The MAS Hz almost touches 2000 Hz, the generally accepted limit with the stock fuel system, but as I remember it is actually the stock ecu that commands the fuel cut at about 2000 Hz.
Timing was around 19 degrees, rpm was only 5700 before backing off, my coolant temp was just under 200 deg F, that's about it! The windows for Fuel Trim Low and O2 Feedback Trim are there but I don't think they mean anything when you are WOT or any open loop condition.

I don't understand how your O2 voltage is 2.5 volts. The narrow band voltage has to be between 0 and 1 volt. You should try to measure your true O2 voltage or better yet get a wideband. You might actually be going lean like I was in this log.

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[TurboTerror99]

Thanks, We're On Boost. I agree that our setups seemed similar at the time so I value your advice. You seem knowledgeable on the subject so I trust your opinion too. Here is some of the newest info. I logged this pull earlier after I changed the temp sensor that was throwing the code. The car ran way better than it did before but it's still black smoking at WOT and doesn't quite feel like it has the pick-up that it should. Thanks in advance!
RPM 6062
INJD 94.5
KNOCK 40
O2-F 2.48V
TPS 57.4%
Cool Temp 206deg
INJP 18.6ms
Fuel Trim 99.2
MAFS 1599hz
EGT 255

 

[We're on Boost]

Hmm, this is pretty interesting.
It's good that you have the MAS Hz and the inj pulse width listed.
Here's a spot in the same log I showed above, where I have similar MAS Hz of 1594 Hz. You can see all the numbers for the cursor position in the "Engine Monitor" window.

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We can almost say that we are having about the same airflow at this instant because the MAS Hz are the same. Not quite though, because the baro and temp corrections are, I think, applied by the ecu on top of the Hz number to correct it. My Hz are straight from the little microphones in the MAS, not from the ecu. Not sure if that is what your Hz number is. But since neither one of us has logged baro or air intake temp numbers, I guess we don't really know. Let's just say our airflows are about the same at this instant! I'm getting more air per intake stroke though because my rpm is a lot lower.

Ok, the fuel amount, hmm, I'm a little foggy on this right now. Your pulse width and mine are almost identical, 18.6 ms vs 18.7 ms. So we are getting the same amount of fuel per intake stroke. Woops, no can't say that because the fuel pressure goes up 1:1 with manifold pressure and neither one of us was logging boost. Well shoot, looks like you'll have to get a wideband if you really want to know your A/F!

It would be good if you had a number for ignition timing. Also it would help if somebody knew why you are getting that weird number for O2 voltage. Maybe somebody who knows more about MMCd could comment.

Knock of 40 sounds awful. Your TPS is only 57% so you are backing off here, you are probably about 0.3 seconds after starting to lift. In the first log I showed you can see a spike in my knock sensor voltage right after I lifted. The ecu picks that up and shelfs it out a ways to the right before it drops it down in steps. So this knock after lifting isn't crazy, but 40 is of course way too high. You can see the knock sum in my second log here is flat 0.
Also I don't understand what your EGT number is supposed to be. Maybe it's a bogus number. 255 sounds a little fishy!

 

[TurboTerror99]

Yeah, there's some interesting information there. Do you think it's possible that my O2 is faulty? That would definitely cause rich conditions AND the strange voltage readings, eh?

 

[We're on Boost]

If you don't know how old the O2 is that is in your car, it could be bad or just off. Practically the first 2 things I replaced on my car when I first got it was replace the O2 sensor and the knock sensor with new Mitsu OEM parts. I have heard people who should know better say that the 1g knock sensors don't even work. I think they work great when they aren't too old. Ah I remember, that was a discussion in the AEM EMS forum. Anyway, a new or newish 1g knock sensor works great with the 1g ecu.

Well having said all that, I really don't think there is any way your O2 sensor could actually be putting out 2.5 volts. It's a nernst cell, if you read about them, they are like a battery, there is no what I would call electronics in it. So I think it's very possible your 2.5 volt O2 readings have something to do with MMCd (which I don't know anything about) or your ecu. I have had 3 ecu's, 2 were bad. The 2 bad ones ran the car but each had a little problem. The only totally good ecu I have is the original 1990 ecu that was in the car when I bought it, and it is non-eprom which is why I'm not using it. Sheesh.

Sorry I'm not giving you anything really definitive to fix your problem here! But it's always good to gather up this kind of info.
If you are handy with wiring and aren't afraid to hack into one of the wires that goes to your ecu, and have a good voltmeter, you could find the signal wire that goes from the O2 sensor to the ecu and check the voltage in it relative to a good ground with your voltmeter clipped onto the signal wire. Then you'd know how many volts that darned thing is really putting out. If you still get weird numbers from it then buy a new one. I redid ALL the wires to my ecu because the plugs were bad and I wanted to relocate it anyway. I'll post a couple of pics for ya. First one shows that the O2 signal wire goes to position 4 on the 1g ecu. It is from the ecu+ manual. Second one is my massive rewire relocate project with the cover off. You can see the heat shrink over all the solder joints, no electrical tape here.

Really I would say, get a wideband first.

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And here's how it looks with the cover on:

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For anybody trying to figure out things from the logs, I need to add a comment about my car at the time. The car had/still has an HKS EVC1 boost controller. As I remember it was set the same as it is now, which is at about 15 psi. That should explain why my logs show 1600 MAS Hz at 5000 rpm, where Derek's car was 1600 Hz at about 6000 rpm, if Derek is running closer to stock boost.

 

[TurboTerror99]

Thanks again, Boost! I need to quit fiddle fartin' and get me a wideband. I'm going to do some investigating and I'll post some more info as it unfolds. BTW, you're a brave soul based on that rewire and relocate. . I would have never tackled that! ha ha

 

[We're on Boost]

Thanks again, Boost! I need to quit fiddle fartin' and get me a wideband. I'm going to do some investigating and I'll post some more info as it unfolds. BTW, you're a brave soul based on that rewire and relocate. . I would have never tackled that! ha ha

Yeah, if you have a good wideband setup going, you'll have one more important piece of info to help you figure everything out.

That rewire/relocate, I thought about that for a long time before I took the plunge. Then once I started it took me I think about 3 months. But I went real slow, made triple sure every step along the way was right, didn't want to be debugging mistakes when it was all done.
Those wires in the upper left area that are going off in a different direction, those go to the ecuplus which is sitting at a 45 degree angle on a little tray under the console. The little tray is suspended by the vertical bar of aluminum you see in the upper middle of the picture.
The cover I made in cardboard first, and thought about it literally for 2 or 3 weeks after that, before cutting and bending the aluminum.

Derek, if you haven't seen this yet, take a look at this thread. This should help you sort out your strange O2 sensor voltages that you are getting from MMCd:

Actually from MMCd's perspective you don't have a front sensor. O2-R is the one and only O2 sensor on a 1G.

 

[TurboTerror99]

Hmm, okay then. So, I'll turn off that setting and log a new one only using the O2-R setting. Thanks for the tip! Maybe that'll shine some light on the subject.

 

[TurboTerror99]

Well, as you and your friend suspected I did in fact need to read the "O2-R" and not the O2-F. I took a casual drive yesterday and changed the O2 setting. Once the car warmed up and I was shifting normally at about 3-4k the logger was picking up the O2 voltage more reasonably. The logger showed it climb from .17v on up to .97v but keep in mind that I didn't have a chance to perform a WOT pull. I was in town and they don't like that. Do these O2 readings seem reasonable or is there a possible malfunction?

 

[We're on Boost]

If you were cruising at a steady speed, as opposed to doing a WOT pull in town , if you were not really accelerating at all when you read those numbers, then you would have been in closed loop operation and the O2 voltage should have been cycling up and down. Probably about 2 or 3 up and down cycles per second. At the top of the cycles you should see a little less than 1 volt, at the bottom of the cycles you'd see about 0.1 volts. So those numbers might be ok, I'm not really sure, because your high number of .97 volts is a little higher than the high number I get which is more like 0.85 volts.

When you log, how many samples per second do you get on the O2 voltage? You need to be able to tell if the voltage is cycling up and down. It's a little confusing if you are just getting snap-shot values 3 or 4 times a second. Know what I mean? The fastest sample rate possible would help with that.

Anyway, in closed loop, your fuel trims would tell you something. There are 4 of them. I don't know enough about MMCd to know how they are named. But if you could log all 4 of them it would help.
There is another MMCd thread where we were talking about closed loop operation. If you haven't seen that thread yet it would help to take a look. Read it all the way to the end though, because I didn't understand the different fuel trims very well at the start of it, and that got better at the end!

http://www.dsmtuners.com/forums/tuning-engine-management/370215-check-my-log-please.html

Be sure to look at post #1 which has the MMCd names of 3 of the fuel trims, and look at post #9 where I show a log cruising at 50 mph and you can see how my O2 voltage is kind of a ragged sine wave up and down about 3 times per second. I didn't log my Mid and High fuel trims though, would have been better with that. Look at post #14. Overall quite a bit of info about closed loop in there.