Last edited by groggory; 05-09-2012 at 11:11 AM.
Just FYI. When the throttle body jumps to totally open, the car IS NOT behaving nicely. I'm getting sputtering and bucking. I held it high for a few moments just so the data on the graph would clearly show it. Afterwards you can see I lift totally off the accelerator. When I lift from the accelerator the throttle body closes back up to idle position roughly.
When I sit in the parking lot with the key-on, but the engine not running, I can slowly modulate the accelerator slowly up, and the throttle body will modulate slowly up with it. As I slowly modulate the accelerator down, the throttle body with slowly modulate down with it.
I'm wondering if the motor in the throttle body is having a hard time keeping the throttle plate partly open under driving conditions and instead it's just flying open.
:-/ Not sure...
Update: Yes, I had done a TB alignment 10 minutes prior to this graph.
Last edited by groggory; 05-09-2012 at 01:15 PM.
Part throttle with MBC's suck.....it's been know since the days MBC and diods. The throttle and throttlebody do not operate on a 1:1 bases like a DBC would. Using the EBC takes away the ability for the ECU to control boost based off load, throttle posistion, and a host of other things.
Is this a new issue you're seeing?
Last edited by T-Boy; 05-09-2012 at 01:59 PM.
Update: Uni Requested the following logs
(RPM - CoolantTemp - LambdaControlValue/InjectionAdj% - Adjustment settings)
(RPM - Air Mass - Throttle Body Angle % - Ignition Angle )
(Lambda Request - Lambda Actual)
001 - 032 - 020
(RPM - CoolantTemp - LambdaControlValue/InjectionAdj% - Adjustment settings)
(Fuel Trim Idle - Fuel Trim Part Load)
(Cyl 1 Ignition Retard - Cyl 2 Ignition Retard - Cyl 3 Ignition Retard - Cyl 4 Ignition Retard)
Last edited by groggory; 05-09-2012 at 04:11 PM.
Even if you have no codes, clear it. It'll clear all block 032 values (fuel trims) and any other stored values and start fresh. I would log all the above and store that so you can send it off to uni, and then reset ECU, and re log the same and compare.
BTW I looked in my ECU, and the EPROM is covered in black epoxy, is this standard practice for UNI?
Last edited by T-Boy; 05-09-2012 at 04:32 PM.
Run 1,2,3 - Blocks 001-003-031
Run 4,5,6 - Blocks 001-032-020
Cleared codes (which resets the fuel trims)
Run 7 - 001-003-031
Run 8 - 001-032-020
All runs were back to back within a minute or so of each other. EBC was set to minimum, which means boost was somewhere around 10-12 PSI. Current temperature is 68 F (20C). All runs are 3rd gear pulls. Fuel pressure was monitored via an in-cabin gauge and looked good; it stayed 43 PSI (3bar) + boost pressure very closely. Boost pressure was monitored via an in-cabin gauge. Replaced plugs with new BKR7E @ .026 gap. The car didn't feel good for these runs. There was some stuttering in the mdidle of the runs but I tried to just ignore it and push through to capture the data. A couple of times I tried to get a run but the stuttering was so bad it wouldn't let the RPM's go up. I could see the cloud of smoke behind me as my tailpipe let loose a torrent of black smoke as it stutters.
Block 020 shows zero's across the board, fyi
Here's the data that Unitronic Requested
Data edited by yours truly
Logs from the 001-003-031 runs
Logs from the 001-032-020 runs
I think it's clear from the graphs...the engine is begging for more fuel. The computer is maxing out it's corrective measures to give it more fuel. The corrective measures keep the engine safe but lead to some seriously rich running on average.
Last edited by groggory; 05-10-2012 at 03:41 AM.
What does "lambda control ok" mean?
Last edited by groggory; 05-10-2012 at 12:23 PM.
I mixed up block 031
In short, my AFR actual is bat **** crazy. My AFR request is spot on.
As such, here is the advice of Unitronic (hats off to them btw, they are doing an excellent job)
Here is the instructions per Unitronic:
The first test that I would like you to perform is to electronically unplug the primary oxygen sensor, but leave the oxygen sensor itself install in the exhaust pipe. Start the car and review Block 031 to make sure that your actual lambda value is at 1.00. If it is not at 1.00 (and is at 1.997) then you likely have a broken oxygen sensor circuit within your ECU itself. If it does read 1.00, let me know and I will proceed with further testing to help you determine the cause of this issue.
Afr actual = 1 with front o2 disconnected
Therefore, the ecu may not be fried.
I'm thinking the ecu isn't reading the o2 sensor for some reason. Perhaps bad wiring.
Here's some preliminary notes I'm figuring out. If anyone knows the pinout of our wideband sensor I'm all ears. I'd also like to know where each wire terminates. I'll do some diagnosis tomorrow afternoon on this.
ecu pin description
5 brown/black heated oxygen sensor g39
51 orange/grey or orange/violet front heated oxygen sensor g39
52 orange front heated oxygen sensor g39 -> front O2 pin 6
63 orange/black rear heated oxygen sensor g108
68 grey/white rear heated oxygen sensor g108
69 grey/red rear heated oxygen sensor g108
70 green front heated oxygen sensor g39
71 black front heated oxygen sensor g39 -> front o2 pin 2
108 blue/orange ground
front o2 sensor pins
green 1 - Rcal
black 2 - Signal Out
blue 3 - Sign In (lp)
white 4 - Heater -
thin white 5 - Sign In (Vs/lp)
grey 6 - Heater +
Last edited by groggory; 05-11-2012 at 01:32 PM.
you have a wiring fault, or you have a bad ecu. Look at your AFR actual values, see them pegging? Thats the value you get with a bad ecu in my experience. have you driven with NO O2 sensor plugged in(and maf plugged in) and logged that(dont do any crazy WOT pulls but watch as things tend to look better) car should still fuel OK to MAP limit, but with maf plugged in it will take a load calculation to injector on time in absence of O2 sensor signal.
Try it LMK
Last edited by RaraK69; 05-11-2012 at 08:50 AM.
Too much good information in this thread.
Can someone please verify the o2 sensor wiring diagram I posted?
I can check my Bentley later, but I think I looked this up before and the Bentley manual, and although it has pinouts for the ECU, it just labels all of the pins as "O2 Sensor" but does not tell me which pin does what. At least we can trace the color wires and go off how the Bosch sensor works:
Bosch part 17014
Red = Heater +
White = Heater -
Black = Signal wire
Gray = signal ground
Yellow = pump circuit (that adds or removes oxygen from the o2) correction factor
Lastly, the pinout is probably in the narrowband to wideband conversion thread. I never looked at it, but it might be in there.
Regardless, tonight here's my plan....
1) Clamp a lead to battery ground and run it over to where I'm working. That's going to be my reference ground for all calculations, diagrams, etc...
2) Go drive the car around so it's up to operating temp. I'm looking for the coolant to be around 190.
3) With the car running, use a fine sewing needle and push it into the o2 sensor wire one by one. Hook each wire up to my oscilloscope (Quant Asylum QA100 Digital Scope + Logic Analyzer) and do a data capture on each wire for a little while.
4) Post up screen caps of each wire with my analysis.
First, I'm hoping this will allow us to know what wire does what. It frustrates me that we blindly follow color codes not knowing what they are doing in a circuit. Actually, as an amateur engineer, I offend myself that I don't know what they do either. So, by this analysis I should be able to post (in here and in my FAQ) what each wire does.
Second, I'll be able to find out if the o2 sensor is actually working. We don't know whether the ECU is reading the oxygen sensor voltage correctly or not. But I do know my oscilloscope works. So, let's ask the oscilloscope what signals the o2 sensor is feeding the ECU.
Third, I'm thinking that even a bad o2 sensor will still spit out a signal. Assuming that the core heater circuit is working I'll proceed with a new o2 sensor. I'll swap in a brand new o2 sensor and repeat the procedure. Let's see if a new o2 sensor puts out a different signal than the old o2 sensor.
I'm hoping that this hour or two of research will help diagnose my problem AND bring more knowledge to the table as to how our cars use oxygen sensors.
Last edited by groggory; 05-11-2012 at 01:53 PM.