Have been stuggling this for a while now...

idle BLM 133 WBO2 14.3-14.3
90 km/h BLM 144 WBO2 14.0-14.3
110km/h BLM 142 WBO2 13.2-13.4

Why is the Readings from WB change? You could see the pattern easy when you scan, from 90km/h to 110km/h the WB reading drops...........

BLM is enabled all the time and Des AFR is 14.7

1. Checked for exhaust leaks.
2. Checked for intake leaks.
3. Relativly new O2 sensor.(heated)

Could a bad O2 cause this or maybe a intake leak from the crankcase?

BLM was around 130 before and WB around 14.3 all the time.....

/N.

 

Yes.
And, timing can effect a difference in WB readings more then the oem O2. Slightly retarding the timing, can generate a lil decrease in the WB AFR reading (richer).

 

Timing at cruise is 45 deg. Will try another O2 otherwise I'll have to change gaskets

Pictures.

AFR tgt is WBO2.

 

next..........

 

Ok...

New O2 - same results
More SA - same results
Less Sa - Same results



any ideas?

/N.

 

Does anything happen around 110km/hr that takes AWAY oxygen or adds fuel?

Examples:
1) AIR gets turned off
2) CCP % is more
etc.

Tim

 

No........running $58 code..........bit status are the same..........

New gaskets on headers and intake!
New plugs and wires- still same results!

There was some oil on 6&8 plugs can they fool the WBO2 showing rich condition? The car doesnt smoke blue, what I'm aware of....

Tomorrow I will switch side on my injectors........otherwise I'm out of ideas......... Will also pull the WBO2 sensor and have a look at it............

Damn! I whant start tuning my F1 unit....but as long as I dont get this right I dont want to put the belt on............

Looking at my latest log:
110km/h BPW 2.9 WBO2 13.0 2250rpm MAP 53kPA
then a small hill came...
110km/h BPW 3.4 WBO2 13.8 2400rpm MAP 61kPA

The trend is clear!

 

Might revisit trying alot less timing.

 

In closed loop open throttle the actual AFR is controlled by two tables. These two tables define the desired NB O2 sensor value. They define the set point of the PID loop. The INT will adjust until the O2 sensor feedback average is within these table limits.

Note that they are based on the current MAP value. This calibration is from a GrandAm.

Other factors come into play when comparing a WB and NB O2 sensor reading. Exhaust temperature and backpressure are major factors when dealing with O2 sensor accuracy.

RBob.

 

Was looking through some old logs and I didnt have this trouble last year, so its probably some "mechanicle issue" the question is what...... Whick sensor should I trust?

Well.............I'll see what happens when I switch side on the injectors and look at the WBO2..........

 

Rbob: I have looked these tables and they look the same in my $58 bin.

I also noticed the O2 swing point is set to 500mV. Was thinking of lower all these values some but I dont know wich sensor to trust.....

/N.

 

picture of diffrent speeds, 55mph-66mph-83mph..

You could clearly see the trend stops after 66mph, the WBO2 stays the same.........

 

I know you said new header gaskets, but have you done anything with the collector gaskets? You may not have to replace them, but try tightening up the collectors and seeing what happens. I've had my fair share of problems with exhaust leaks.

Reminds me I need to tighten up my header bolts now that I broke in the cam yesterday...

 

Yea, Ive tightening the collector.......

I'll get back after I've swapped the injectors.......

 

Ok, didnt have time to swap injectors but I did unplug the WBO2 and on one side it was white, looks like it could have been "siliconed" will this force it to show rich at higher rpm's?

Recalibratet the WBO2 at took it for a drive.

At idle the WBO2 seems to show right.
But at 90 and 110 km/H its still the same- rich

Also If Im driving in 90km/h in (D) and switching to D, the WBO2 drops off exactly as it does when I go from 90->110km/H i (D) so its depending on rpm...........

Grumpy: lowered the cruise timing more and my headers started to glow....

Well, Time to take the dog out for a walk and go to bed.........Will swap the injectors tomorrow and order a new WBO2, just in case.......

 

Update:

Changed the injectors between LH/RH. Same resuts.........

At 50 km/h @ 1500 rpm WB= 14.7 BLM 142 MAP 52
At 90km/h @ 1850 rpm WB= 13.5 BLM 142 MAP 49
At 110km/h @ 2200 rpm WB= 12.7 BLM 142 MAP 47

Then I unplugged the Aux input to LM1

At 50km/h @ 1500 rpm WB= 14.0 BLM 134 MAP 50
At 80km/h @ 1650 rpm WB= 13.8 BLM 135 MAP 50
At 110km/h @ 2200rpm WB= 13.5 BLM 139 MAP 49 this has always been lower before..

I also checked for AC current and I had 30v between the +/- nomather what rpm on engine, is this normal?

Anyone with more ideas? I'm out......................

 

When you look at a vehicle speed and RPM for a WB and BLM comparison, you really need to be including the MAP/vacuum reading. The MAP and RPM are what affects the BLMs....

 

Myself and RBob already touched on this - but I just want to drive it home a little bit.

IF ... and this is a big IF .. IF you don't have a mechanical problem then the difference is because the ECM is targeting a different mean O2 mV. This can be do to many things ... like the AIR and CCP that I mentioned ... or the MAP that RBob mentioned.

I know that the 8D changed the mean O2 ~100mV for stuff like AIR and like ~70mV between the max/min kPa in the tables. Remember that a change in speed also changes MAP (as perviously pointed out).

Tim

 

I checked my new plugs I put in and they seemd OK. So I dont think I have any leaks or mechanical probs.

My $58 bin has same swing points ..........

 

swap O2 sensors side to side. See if it's still the same (may need to run a jumper wire of course).

 

Good idea. He did swap injectors side to side and that would take care of fueling irregularities but it wouldn't take care of fresh air irregularities due to a leak.

Tim

 

Did you add those constants / tables to TC ?

Or is my $58 defs REALLY out of date?

I talked to TC a few weeks ago about adding a ton of constants to $60 tdf, but they haven't done it yet as far as I know.

-- Joe

 

* Will try switching the O2's
* Will also try power the WB from a battery on the floor to rule out if the alternator is disturbing the signal....

* I've added alot of things to TC def. file. I had to remove some constants to be able to add new ones.......The 415cui do run nice with $58 code....The speedshops here in sweden dont beleve me when I tell them what EFI system I have (730ECM with chip from syclone +WB)

I did get the EGR tgt to operate in the area where I want it, so I can try change the BPW depending on EGR tgt like HGW mode, but thats another topic.

Another evening in the garage............

I checked the price for a Bosch sensor at my local dealar- 387$ The Swedish Innovate distributor charged only 121$ so I ordered one, should be here tomorrow, then I can rule the sensor out.......too...............

 

Switched the O2.... Now the WB is showing lean so its something with the LH side. Looked at the new plugs and no 5&7 looks a litte leaner but not much. So I guess its the way my engine is with my combo.....

So now I turn off BLM at 1200rpm with open throttle and just tune with the WB in LH header (the leanest one). I still Use the BLM at idle for now..........

Later I probably will put the engine in a Superflow bench..to check everything...... But I need a custom harness first....Will also continue to check my plugs often......



/N.