Ok, so I finally sat outside and pulled the damn carpet up to get to the ECU. I plugged the white wire from my apexi autotimer into the black wire from the o2 sensor wire.

http://www.apexi-usa.com/productdocu...structions.pdf

The manual comes with like 3 sections on how to "configure it."(Page 2, column 3) Can someone explain this to me?

Right now I THINK I set them to 10.0 and 960. At idle, the a/f reads 20.0, and under full load around redline, it's at like 14.5. Also, when I downshift to slow down, it's at like 20.

Is it configured correctly? If not, what do I do? What readings should I be getting?

Thanks, Jack

Edit: These numbers are with FCD disconnected and it running up to ~10psi

 

Are you reading this off a wideband sensor, or?

14:1 @ full load is going to end your engine right quick and in a hurry.

 

This is off my crappy narrowband o2 with my apexi crappety gauge with my FCD pulled out. What is going on?!?!?!
Edit: I'm going back outside. Be back in 30.

 

The narrow band are not very accurate, so I wouldn't trust them entirely. Under decel/slowing down it'll show lean obviously, but you can't really get a good idea with the narrow.

 

Ok, it ran up to .8mV under WOT (o2 voltage) but that showed 14.0 under A/F. Is my engine going to blow up? (This is still with FCD disconnected)

 

Fuel Ratio - Voltage
17.0 - 0.1
16.0 - 0.2
15.5 - 0.3
15.0 - 0.4
14.7 - 0.5
14.6 - 0.6
14.5 - 0.7
14.2 - 0.8
13.2 - 0.9
12.5 - 1.0

Found this chart. Why isn't my o2 voltage reading up to 1.0? Is it really not getting that? Did I tap the wire wrong? I tapped in right before the ECU.

 

I just want my car to be reliable!!!

 

ideas?

 

any ideas of how to rectify the problem? or to verify that my car isn't running dangerously lean?

 

that o2 sensor is good for very vague readings only...i actually hooked a multi meter up to it and drove around one day. what i got was basically close to .9-1 on accel and almost no voltage ~.1 on decel...in between i found it dancing all over the place. i wouldn't trust it for anything more than what the factory uses it for...polling for low load cruise closed loop fuel delivery mode for freeway driving. wow that was a mouthful :p

 

my voltages aren't going up to 1v tho My car is basically stock. What's going on? Seriously, could I not have made a good enough contact with the o2 sensor wire?

 

I have the same timer.... play with the thing to get it to read about 13.5 at idle.....

Remeber, its just an indicator, its not real accurate.. when I compared the readings off that to a wide band running at the same time,,, it would bounce around and would be plus or minus about 2 points!!!!!

Don't freak out tooo much about that apexi timer a/f reading.... but like i said, with the stock computer and the apexi running off the stock o2 sensor, mine read about 13.5 at idle and the wideband showed about 13.3... but.... under driving conditions, it was pretty much a shot in the dark compared to the wideband.

 

the O2 sensor in your car may also be shot in the *** too and therefore won't be giving correct voltage readings

the thing is working.... however, it's correction factor is WAY off.. if its reading 20 at idle and 14.1 at FWO, then the car is getting richer under full boost,,,, which is supposed to happen, but those numbers aint right.


With my stock setup.... 13.3 at idle and 12.2 at about 11 PSI. SOOOOO you need to get the correction factor figured out to have it show something in that ballpark. I'll see if i have my directions out in the garage and get back to ya.

 

awesome. Thanks YOD. I tried messing around with settings but couldn't see any changes. Do you have any ideas that could do it?

 

Closed loop? Where is a good place to learn more about that?

 

Ok, still no luck with this. Does anyone have any suggestions. The only thing that is making me question it is that I used the little connector thing that was supposed to be used for the ebrake to connect the white wire to the 02 wire. What else could be wrong?

 

Are you telling me you are trying to get an accurate a/f reading from the stock narrowband? LOL...ain't gonna happen.

-Joe

 

I'm not trying to get accurate, I want ballpark. Right now, it reads 20 at idle and 14 at WOT. WTF. It's got to be a little more accurate than that.

 

I don't have the right settings for the timer im sure, I didn't know what they were supposed to be at. I'll take a look at my A/F on my way home from work at lunch.

I think since you're way off at 20 at idle you may just have the settings off. I'll see what mine are at and let you know..

Since mine wasn't acurate either, personally I just ignored it and used it as a volt meter... until someone else brought up the subject of the proper settings. Since I didn't know them..

 

my voltages only go up to about .85 max... that's why i was thinking, the little connector (easy splicer) i used isn't making a good connection. If those are really what the 02 sensor is seeing, either my car should have blown up years ago, or i need a new 02 sensor.

 

For starters I don't know why you'd waste money on a turbo timer, but that's another discussion.

Personally I would not be trusting any device that attempts to convert narrow-band O2 sensor readings into AFR numbers. It's just not possible because the sensor's output varies so widely with temperature.

If you think the numbers are suspect then simply measure the voltage of the O2 sensor directly while driving (i.e. DMM on ECU pin 2C). It should be near zero on decel, oscillate around 0.5V during cruise and be close to 1.0V at full load. If the readings aren't close to that then replace the O2 sensor. If they're what they should be then the "AFR" readings on the TT are bogus and should be ignored.

BTW, ECU connections should really be soldered.

 

Ok NZ, the voltage doesn't go up to 1. The most it will go to is about .85. It drops to zero on decel.

This is my plan of attack. Tell me if it's ok.

1. Reattach the TT wire at the ECU wire2wire. (no little connector doohickey)
2. Replace 02 sensor.
3. Cry because my car will blow up.

 

The o2 sensor is probably a few years old, and the voltages it's putting out is whack. There is no way you're going to get a precise air/fuel number by converting the stock narrowbands voltage signal. I wouldn't bother trying so hard.

I know NZ likes to stick up for narrowbands, but honestly I think they're pretty worthless. If you really are interested in what the narrowband is saying, tap into the voltage wire with a multimeter and watch the voltages.

After looking at your mods, and not spotting anything that is tuneable I'd suggest making a pull or two on your local dyno using their wideband. I imagine you just want to make sure you're a/f numbers are safe under WOT. Usually you can get 2 pulls for 25 or 30 bucks when local car clubs hold groub dyno days.

 

I'd just replace the sensor. If the connection's bad you'll just get nothing. It's highly unlikely a basically stock car is going to blow up due to lean mixtures. If you're really worried, get it dyno'd.

A lack of understanding does not make something worthless. You think it's worthless because you want to use it for reading full-load mixtures. That's like saying a an oil pressure gauge is worthless because you want to use it to read oil temps. Not only does a working O2 sensor make the engine run better and use less gas, it can be used to spot mixture changes that indicate probems. How is that worthless?

Persoannly I wouldn't waste my money buying a brand-name A/F meter, because I don't think they're that important, but the $10 DIY one I have does the job perfectly.

 

bought new O2 today (before NZ's post ) I'll let you all know how it goes... before that gets done.... I'm respraying my weather strips...