CalG

300 miles to drive Sunday (Brattleboro To Burlington VT and Return


Average speed about 75 mph.
Trip display average for the day, 69 mph

Actual fuel consumption divided by miles driven
22.5 Miles per gallon (US)

trip display 23.7 mpg

I'm OK with that. We were very comfortable.

Funny, the Cruise Control worked recently, but was non-op Sunday morning.
I couldn't see any VAG diagnostics for the 1999 cars. 2000+ have it all.

Oh Well.



CalG

PaulW

When I replaced my TPS I broke the little do-hicky thing that retains the mechanical linkage from the vacuum diaphram to throttle so mine is now out of commission until I get a new one.

Does your car still hunt at 40 or so MPH?

Mine is still working great, sometimes when it is in 5th and the speed drops to less than 41 MPH it will hunt ever so slightly until I lift or if I give it a little gas and it downshifts to 4th....but that's somewhere around 1,000 RPM in 5th.

Other than that....it's still perfect around town.

CalG

Paul

Good thought about the vacuum hardware and linkage. That was my first thought last night when considering the CC. First look to recent changes. I do need to take a look at any hardware changes and reinstall after replacing the TPI. It was cold, I could have missed something. But, now it's even colder ;00

This car still hunts in the upper gears when pressed to accelerate at reves between idle and about 2000. If the call to action includes a gear change, the hunt is lost in the transition.
(That's good)! In the data logs, I still see the correlation between fluctuating TCC control,
Transmission slip status, and now "engine torque" as shown in field 1 of group 9. Do you know how that engine troque value is calculated? anyone? RPM X injector function?

Acting from an entirely different approach, I am going to replace the front two Oxygen sensors. The hunch is regarding "event timing". It's a stretch, and I need a bit of help. But as I look at the Diagnostic Mode 5 in the eBahn service book, there is a Reference for "Upper and lower Voltage for shift time calculation". This is interesting, unless the "shift timing" has nothing to do with the Transmission ;-)

Hmm.. this is something new. even if I have heard of the suggestion to replace O2 sensors previously. Are there any with this experience?

Since this car also just turned 100K (sorry no photos of the odometer) refreshing the O2 sensors is likely a good idea even if only for the promise of enhanced fuel efficiency.

Following the service reference I tried to access group 5 under 01 engine, With Vag-COM but was not allowed that access. The difference between Generic Scan tool and The VAG-COM I suppose.

Can anyone help with a useful procedure to measure and record the O2 sensor signals so that a before and after comparison of data can be made?

When you come to a fork in the road, take it!

Regards

CalG

PaulW

When I did the tranny change out you have to pull the exhaust from the manifold so when it's on the ground I changed the two front 02 sensors with generic bosch sensors.

That did not change my hunting or torque converter drop out any.

Hex168

CalG, it sounds like you are in Vermont. I have not had to do O2 sensors yet, but there are some old posts in the C4 forum that indicate that the low temperature behavior of the O2 sensors is inferior for the generics than for the OEM. No idea why, but I recall that the original poster was EXTREMELY knowledgable. It supposedly only mattered for the front O2 sensors.

CalG

I have selected "wired to fit" Bosch units from one of the on-line parts houses. $125 each.
In order to avoid disapointment, I have no expectations .

Common knowledge says fresh devices will promote proper engine operation, if nothing more.

Moreover, the Bosch specialist implied that diagnosing the behavior of an ECM or TCM without first qualifing the O2 sensors is ill advised. At milage of 100k, to "test" the O2 sensors costs more than they are worth. So to be on the favored side of the information curve, these sensors will be exchanged when the new items arrive.

I have also heard that application specific sensors may be justified by enhanced performance. Something about geometries and shielding of the active elements to enhance the desired functionality.

Technology is the answer... What was the question?

CalG

Always Overcharged

The sensors can be monitored with vagcom and when mine were bad I logged data and scoped it as well.
The measuring block spec for the o2 were between +12 and -12 with engine warm -mine were all over the place due to a faulty evap valve and one dodgy sensor.
After repair they stay between -5 and +5 most of the time under normal driving conditions.
In New Zealand and most other countries other than the US the rear sensors are not OEM as the Govt does not requie ommision testing as yet.
Here is a sample log taken recently.
Group '011
Lambda Lambda Voltage Voltage

% % V V
0.8 1.6 0.095 0.12
1.6 0.8 0.76 0.815
-0.8 -0.8 0.805 0.84
-3.1 -3.1 0.78 0.815
-4.7 -5.5 0.445 0.69
-0.8 -1.6 0.085 0.075
0.8 0 0.09 0.075
3.1 2.3 0.115 0.095
1.6 0.8 0.86 0.855
-4.7 -2.3 0.675 0.16
-3.9 -5.5 0.08 0.215
3.1 2.3 0.18 0.095
-4.7 -3.1 0.1 0.775
-3.1 0.8 0.655 0.095
-3.9 -2.3 0.835 0.865
-6.3 -5.5 0.805 0.82
-4.7 -7 0.095 0.69
-2.3 -3.9 0.075 0.065
-0.8 -1.6 0.075 0.065
1.6 0.8 0.08 0.07
3.9 3.1 0.09 0.08
6.3 4.7 0.255 0.14
1.6 1.6 0.645 0.755
4.7 3.1 0.14 0.105
1.6 1.6 0.655 0.755
4.7 2.3 0.155 0.12
1.6 4.7 0.665 0.33
5.5 3.9 0.105 0.08
1.6 -0.8 0.785 0.75
-3.9 -6.3 0.775 0.54
-5.5 -8.6 0.73 0.115
-7.8 -7.8 0.59 0.22
-2.3 -2.3 0.095 0.09
-4.7 -4.7 0.77 0.815
-7 -7 0.125 0.745
-1.6 -3.1 0.065 0.06
1.6 2.3 0.8 0.815
-3.1 0.8 0.115 0.11
-3.9 -2.3 0.81 0.845
-6.3 -4.7 0.825 0.85
-6.3 -7 0.085 0.37
-3.9 -3.1 0.07 0.07
-1.6 -0.8 0.07 0.075
2.3 3.9 0.07 0.075
5.5 3.1 0.15 0.765
0.8 1.6 0.8 0.84
-1.6 -0.8 0.65 0.755
2.3 2.3 0.105 0.095
4.7 3.9 0.16 0.135
0.8 0.8 0.725 0.78
3.9 2.3 0.12 0.165
0.8 1.6 0.68 0.72
3.9 2.3 0.155 0.125
0 0.8 0.625 0.785
3.9 -1.6 0.405 0.56
-0.8 2.3 0.605 0.115
3.1 -0.8 0.17 0.74
-0.8 1.6 0.195 0.11
0.8 -0.8 0.69 0.75
-1.6 1.6 0.67 0.11
1.6 0.8 0.195 0.175
0.8 -0.8 0.105 0.11
-2.3 -3.1 0.725 0.295
-0.8 0.8 0.81 0.83
-4.7 -4.7 0.725 0.79
-5.5 -2.3 0.545 0.34
-4.7 0.8 0.715 0.13
-3.1 0 0.76 0.505
-2.3 -0.8 0.725 0.785
-3.9 -2.3 0.735 0.745
1.6 6.3 0.765 0.225
1.6 0 0.805 0.795
0 -0.8 0.09 0.08
-1.6 -2.3 0.785 0.79
-3.9 -4.7 0.795 0.81
-6.3 -3.9 0.09 0.09
-1.6 -1.6 0.065 0.06
1.6 1.6 0.055 0.06
7 7 0.775 0.775
0.8 2.3 0.77 0.135
0 0.8 0.105 0.1
0 -0.8 0.785 0.81
-2.3 -3.1 0.84 0.85
-3.9 -4.7 0.095 0.095
0 -0.8 0.075 0.07
-1.6 0 0.085 0.1
-1.6 0.8 0.08 0.775
0 -0.8 0.82 0.84
-1.6 0.8 0.095 0.09
-3.9 -5.5 0.1 0.65
2.3 0.8 0.805 0.81
0.8 3.9 0.77 0.355
-3.9 -3.1 0.29 0.825
-3.9 -3.1 0.375 0.735
-3.1 -0.8 0.075 0.075
-1.6 -2.3 0.415 0.665
3.1 2.3 0.67 0.18
-1.6 -2.3 0.745 0.765
-4.7 0 0.74 0.25
-3.9 1.6 0.325 0.175
0 1.6 0.195 0.21
-0.8 1.6 0.1 0.095
2.3 3.1 0.095 0.12
0.8 2.3 0.115 0.095
-0.8 1.6 0.095 0.165
0.8 2.3 0.085 0.1
-3.1 -2.3 0.73 0.815
-1.6 -5.5 0.09 0.77

Always Overcharged

The car ran like a pig with this-
Group'011
Lambda Lambda Voltage Voltage

% % V V
-25 -25 0.94 0.935
-25 -25 0.94 0.935
-25 -25 0.935 0.935
-25 -25 0.935 0.93
-25 -25 0.935 0.93
-25 -25 0.935 0.93
-16.4 -16.4 0.06 0.09
7.8 7.8 0.08 0.09
22.7 21.9 0.645 0.165
25 25 0.065 0.08
25 25 0.045 0.055
25 25 0.045 0.05
25 25 0.045 0.045
25 25 0.04 0.045
25 25 0.055 0.06
21.9 21.9 0.815 0.79
14.8 15.6 0.875 0.875
10.2 10.2 0.915 0.915
5.5 5.5 0.925 0.92
0.8 0.8 0.925 0.92
-4.7 -4.7 0.895 0.88
-10.2 -3.1 0.625 0.165
-6.3 -3.1 0.055 0.07
3.1 7 0.035 0.04
20.3 24.2 0.035 0.04
25 25 0.045 0.05
25 25 0.115 0.12
25 25 0.15 0.205
19.5 20.3 0.74 0.765
18.8 19.5 0.75 0.77
20.3 21.1 0.755 0.19
17.2 18 0.755 0.18
8.6 8.6 0.81 0.8
3.1 5.5 0.755 0.24
-3.1 -2.3 0.8 0.81
-8.6 -7.8 0.89 0.89
-14.1 -13.3 0.89 0.895
-19.5 -18.8 0.87 0.875
-24.2 -23.4 0.085 0.165
-17.2 -16.4 0.07 0.075
-10.9 -10.9 0.075 0.08
-5.5 -7.8 0.305 0.6
-9.4 -8.6 0.12 0.12
-5.5 -5.5 0.64 0.725
-4.7 -4.7 0.13 0.15
-5.5 -5.5 0.715 0.715
0.8 0.8 0.16 0.185
-3.9 0 0.135 0.14
-4.7 -2.3 0.325 0.13
0.8 -2.3 0.72 0.72
1.6 -0.8 0.18 0.74
-3.9 -1.6 0.13 0.105
0 -1.6 0.735 0.695
3.9 3.9 0.075 0.08
14.8 14.8 0.04 0.045
25 25 0.085 0.075
17.2 16.4 0.755 0.74
1.6 6.3 0.775 0.85
-6.3 -9.4 0.72 0.475
2.3 0.8 0.77 0.75
-5.5 -6.3 0.1 0.12
-3.1 -4.7 0.77 0.71
-10.2 -11.7 0.88 0.885
-16.4 -18 0.9 0.91
-22.7 -24.2 0.81 0.805
-24.2 -25 0.83 0.845
-25 -25 0.88 0.9
-18 -18.8 0.07 0.065
-24.2 -24.2 0.91 0.92

Always Overcharged

I have these logs as excel files for email if anyone requires them in an easier to read format

CalG

Ahh! Thanks so...
Engine Group 01
Function 11, blocks ???

Is there a reference for which is Bank 1 and Bank 2?

I'll log on the drive home.

I have made inquiry to Ross-Tech as well.

The response time is the performance aspect that changes with age.

Voltage levels will be "adjusted" by contamination.:-(

Regards

CalG