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Hello,

I have some serious boost & performance issues on my car (S3 8L -> http://www.rs246.com/index.php?name=PNp ... ic&t=63721) and after checked & replaced almost everything, i would to check the lambda sensors, I have VAG COM but do not know how to do ? Could someone help please ?

many thanks

Looking at your other post your maf readings are suggesting 225 - 243 bhp, I suspect you should expect more than that.

I think a lambda fault will show if you scan the engine module for fault codes.

I'm more inclined to suspect the maf as I think on the S3 the boost is controlled by the maf readings.

yorkie wrote:Looking at your other post your maf readings are suggesting 225 - 243 bhp, I suspect you should expect more than that.

I think a lambda fault will show if you scan the engine module for fault codes.

I'm more inclined to suspect the maf as I think on the S3 the boost is controlled by the maf readings.

Thx for the answer, indeed you are right the car is not pulling as it should. Btw i replaced the MAF yesterday but just feel a slight difference, but the target boost is not reached yet, there maybe something else..

For the lambda, i have no error code at all, thats why it so hard for me to find the problem..

any clue will be greatly appreciated !

thx !!!!

If the ecu is requesting full boost the car is not in limp mode so a boost leak maybe?

yorkie wrote:If the ecu is requesting full boost the car is not in limp mode so a boost leak maybe?

I didn't know that, thx for this info, ECU requests 2500 mbar between 3000 rpm and 4000 rpm :


Wednesday 15 August 2007 20:45:12
8N0 906 018 BH 1.8L R4/5VT G 0001

Group A: '115 Group B:
Engine Speed Load Cmd Pressure Press @ Intercool
TIME TIME
MARKER STAMP /min % mbar mbar STAMP
6.03 2160 95.5 2240 1230 1010
6.43 2320 102.3 2490 1300 1190
6.83 2440 112.0 2550 1400 1150
7.25 2640 122.6 2530 1530 1000
7.74 2880 139.1 2550 1760 790
8.25 3120 162.4 2550 2020 530
8.65 3360 174.4 2550 2220 330
9.15 3680 181.2 2550 2270 280
9.66 3960 177.4 2550 2230 320
10.16 4280 174.4 2550 2180 370
10.56 4520 171.4 2550 2160 390
10.96 4720 170.7 2490 2060 430
11.37 4920 163.9 2450 2070 380
11.87 5200 160.9 2440 1980 460
12.27 5400 158.6 2420 1930 490
12.72 5600 157.9 2390 1930 460
13.33 5880 154.1 2300 1920 380
13.78 6080 153.4 2230 1830 400
14.18 6240 145.9 2190 1890 300
14.59 6400 149.6 2170 1860 310
14.98 6520 143.6 2170 1860 310
15.39 6680 137.6 2150 1840 310
15.79 6800 141.4 2050 1830 220

No it's not in limp mode, it looks like a leak. But make another log from 118.
And to look for lambda, make a log from 099 and 31.

Regards,
Jeroen

RSjd wrote:No it's not in limp mode, it looks like a leak. But make another log from 118.
And to look for lambda, make a log from 099 and 31.

Regards,
Jeroen

Thanks ! I will log these groups and post them asap !

Still say a boost leak or failing turbo (hope not the latter) Doug at MRC is the man to see, If he can't fix it he will certainly be able to tell you what is broke.

RSjd wrote:No it's not in limp mode, it looks like a leak. But make another log from 118.
And to look for lambda, make a log from 099 and 31.

Regards,
Jeroen

Hi,
Here are the logs :

Sunday 2 September 2007 21:36:34
8N0 906 018 BH 1.8L R4/5VT G 0001

Group A: '118
Engine Speed Intake Temp N75 Duty Cycle Press @ Intercool
TIME
MARKER STAMP /min ｰC % mbar
0.39 720 45.0 0.0 980.0
25.34 1440 39.0 0.0 1050.0
26.23 1280 41.0 84.3 1030.0
27.04 1480 39.0 84.3 1090.0
27.94 1800 37.0 84.3 1170.0
28.75 2080 36.0 84.3 1270.0
29.55 2400 35.0 0.0 1320.0
30.37 2520 36.0 0.0 1070.0
31.27 2560 38.0 0.0 1010.0
32.18 2560 39.0 0.0 990.0
33.09 2680 41.0 0.0 1000.0
33.89 2800 40.0 0.0 1010.0
34.69 3000 39.0 84.3 1220.0
35.49 3480 37.0 84.3 2050.0
36.31 4040 35.0 84.3 2190.0
37.20 4640 33.0 84.3 2100.0
38.11 5240 34.0 84.3 2040.0
38.91 5680 35.0 84.3 1920.0
39.73 6120 36.0 84.3 1900.0
40.64 6560 38.0 84.3 1920.0
41.54 6840 39.0 0.0 2110.0
42.34 6000 39.0 0.0 1170.0
43.14 5240 40.0 84.3 2150.0
43.95 5240 39.0 0.0 1200.0
44.85 4840 39.0 0.0 1040.0
45.65 4480 40.0 0.0 1010.0
46.46 4320 42.0 0.0 1010.0
84.28 2520 36.0 84.3 1210.0
85.18 2840 33.0 84.3 1720.0
85.99 3280 32.0 84.3 2260.0
86.89 3880 30.0 84.3 2250.0
87.69 4320 30.0 84.3 2160.0
88.51 4800 32.0 84.3 2090.0
89.51 5360 33.0 84.3 2000.0
90.41 5840 34.0 84.3 1980.0
91.42 6280 36.0 84.3 1970.0
92.33 6640 39.0 84.3 1870.0
93.14 6840 39.0 0.0 2180.0
93.94 6840 39.0 0.0 1280.0
94.94 5320 39.0 0.0 1070.0





Group B: '115
Engine Speed Load Cmd Pressure Press @ Intercool
TIME
STAMP /min % mbar mbar
0.89 720 21.8 980.0 980.0
25.83 1280 60.9 1150.0 1000.0
26.64 1400 76.7 1510.0 1060.0
27.44 1600 80.5 1600.0 1120.0
28.36 1920 89.5 1830.0 1210.0
29.16 2280 106.8 2450.0 1350.0
29.95 2480 23.3 980.0 1170.0
30.87 2520 13.5 980.0 1030.0
31.68 2560 13.5 980.0 1010.0
32.58 2640 28.6 980.0 1000.0
33.49 2760 24.1 980.0 1010.0
34.29 2880 75.9 2520.0 970.0
35.09 3200 130.8 2550.0 1580.0
35.91 3760 180.5 2550.0 2260.0
36.71 4320 175.9 2550.0 2140.0
37.62 4920 168.4 2450.0 2080.0
38.51 5480 163.9 2430.0 1990.0
39.31 5920 170.7 2300.0 1970.0
40.13 6320 159.4 2190.0 1930.0
41.14 6760 145.9 2080.0 1890.0
41.94 6680 18.0 980.0 1470.0
42.74 5120 106.8 2410.0 1290.0
43.54 5200 14.3 980.0 1670.0
44.45 5040 12.0 980.0 1070.0
45.25 4680 12.0 980.0 1020.0
46.07 4360 12.0 980.0 1010.0
46.86 4280 12.0 980.0 1010.0
83.89 2440 71.4 1180.0 1160.0
84.78 2680 120.3 2530.0 1470.0
85.58 3040 168.4 2550.0 2040.0
86.49 3600 182.0 2550.0 2260.0
87.29 4080 177.4 2550.0 2160.0
88.11 4560 173.7 2500.0 2140.0
89.00 5080 168.4 2410.0 2050.0
89.91 5600 164.7 2390.0 2000.0
90.92 6040 159.4 2240.0 1930.0
91.83 6440 149.6 2130.0 1950.0
92.73 6760 144.4 1970.0 1920.0
93.55 6840 60.9 990.0 1340.0
94.44 6080 12.8 990.0 1150.0

Sunday 2 September 2007 21:39:23
8N0 906 018 BH 1.8L R4/5VT G 0001

Group A: '099 Group B: '031
Engine Speed Coolant Temp Lambda O2S1 Voltage O2S2 Voltage
TIME TIME
MARKER STAMP /min ｰC % STAMP
0.49 760 92.0 3.1 O2-Reg.ON 0.01 0.953 0.945
49.39 1560 97.0 -1.6 O2-Reg.ON 49.78 1.023 0.992
50.20 1800 97.0 1.6 O2-Reg.ON 50.69 1.000 0.992
51.21 2120 97.0 0.0 O2-Reg.OFF 51.70 0.992 0.992
52.10 2600 97.0 1.6 O2-Reg.ON 52.50 0.977 0.992
52.90 2280 98.0 0.0 O2-Reg.OFF 53.30 0.945 0.992
53.70 2120 97.0 0.8 O2-Reg.OFF 54.10 0.961 0.977
54.50 2400 98.0 0.0 O2-Reg.ON 54.92 0.953 0.953
55.32 2800 98.0 -1.6 O2-Reg.ON 55.72 0.891 0.953
56.13 3320 98.0 -0.8 O2-Reg.ON 56.63 0.953 0.953
57.03 4040 98.0 -1.6 O2-Reg.ON 57.43 0.945 0.953
57.85 4600 98.0 -1.6 O2-Reg.ON 58.34 0.961 0.953
58.74 5200 98.0 -0.8 O2-Reg.ON 59.14 0.961 0.953
59.65 5720 98.0 0.0 O2-Reg.ON 60.05 0.945 0.953
60.45 6160 98.0 0.0 O2-Reg.ON 60.85 0.938 0.953
61.25 6520 98.0 0.0 O2-Reg.ON 61.65 0.961 0.953
62.07 6840 98.0 -0.8 O2-Reg.ON 62.47 0.984 0.922
62.87 6440 98.0 2.3 O2-Reg.OFF 63.27 0.797 0.891
63.67 5200 98.0 0.0 O2-Reg.OFF 64.08 0.750 0.891
64.47 5240 98.0 0.0 O2-Reg.OFF 64.88 0.867 0.945
65.28 5160 98.0 0.0 O2-Reg.OFF 65.68 1.991 1.047
66.18 4920 98.0 0.0 O2-Reg.OFF 66.58 1.991 1.047
100.77 1800 87.0 0.0 O2-Reg.OFF 101.18 0.977 0.992
101.70 2240 87.0 -0.8 O2-Reg.ON 102.19 0.992 0.992
102.59 2720 87.0 -2.3 O2-Reg.ON 102.99 1.000 0.992
103.39 3040 88.0 -0.8 O2-Reg.ON 103.81 0.992 0.992
104.21 3360 87.0 -0.8 O2-Reg.ON 104.61 0.969 0.992
105.01 2520 87.0 0.0 O2-Reg.OFF 105.41 0.953 0.992
105.81 2360 88.0 -1.6 O2-Reg.ON 106.22 1.008 0.992
106.62 2400 87.0 -1.6 O2-Reg.ON 107.12 0.984 0.992
107.52 2440 88.0 -3.1 O2-Reg.ON 107.92 0.984 0.992
108.34 2480 88.0 -3.9 O2-Reg.ON 108.73 0.984 0.992
109.23 2560 88.0 -3.1 O2-Reg.ON 109.74 0.992 0.992
110.14 2600 88.0 0.8 O2-Reg.ON 110.54 0.992 0.992
2 110.94 2680 88.0 0.8 O2-Reg.OFF 111.34 1.008 0.992
111.74 2720 88.0 0.8 O2-Reg.OFF 112.14 0.977 0.969
112.56 3040 88.0 0.8 O2-Reg.ON 113.05 0.984 0.953
113.45 3560 88.0 2.3 O2-Reg.ON 113.97 0.945 0.953
114.46 4160 88.0 -0.8 O2-Reg.ON 114.86 0.961 0.953
115.26 4640 88.0 -0.8 O2-Reg.ON 115.66 0.961 0.953
116.08 5120 89.0 -0.8 O2-Reg.ON 116.57 0.961 0.953
116.97 5600 89.0 -0.8 O2-Reg.ON 117.37 0.906 0.953
117.79 6000 89.0 0.0 O2-Reg.ON 118.19 0.945 0.953
118.59 6320 89.0 0.0 O2-Reg.ON 119.00 0.938 0.953
119.50 6640 90.0 0.8 O2-Reg.ON 119.90 0.899 0.875
120.41 6840 90.0 0.0 O2-Reg.OFF 120.81 0.774 0.782
121.31 5200 90.0 0.0 O2-Reg.OFF 121.81 0.750 0.805
122.20 5080 90.0 0.0 O2-Reg.OFF 122.70 0.821 0.875
123.12 4960 90.0 0.0 O2-Reg.OFF 123.52 1.991 1.047
124.01 4800 90.0 0.0 O2-Reg.OFF 124.41 1.991 1.047
124.83 4680 90.0 0.0 O2-Reg.OFF 125.23 1.991 1.047

If you need more let me know !

Thx !!

Jeroen, you wouldn't be the famous G60 tuner by any chance?

Sorry for the delayed reply...

The lambda is good, because the lambda read follows nice the requested lambda, and with a very acceptable correction (099) less 5%.
But your boost is much lower than the requested boost. The N75 is (for some reason??) limited on 84,3%, to get the target/requested boost, it needs a little bit more, about 90-95% and at higher revs to 100%, but that has to be done in the software. If you have a N75 ...c version, you can try a ... F version. Or you can adjust the connection rod from the wastegate, make it about 4mm shorter/stiffer. But be carefull and check the boost, don't go over 2500mbar !!!
If this doesn't work, than there's a leak. Goodluck. Sorry for my Englisch..

Yes I think it's me .i've done a lot with G60's ... Blue Golf mk1


BR,
Jeroen

RSjd wrote:Sorry for the delayed reply...

The lambda is good, because the lambda read follows nice the requested lambda, and with a very acceptable correction (099) less 5%.
But your boost is much lower than the requested boost. The N75 is (for some reason??) limited on 84,3%, to get the target/requested boost, it needs a little bit more, about 90-95% and at higher revs to 100%, but that has to be done in the software. If you have a N75 ...c version, you can try a ... F version. Or you can adjust the connection rod from the wastegate, make it about 4mm shorter/stiffer. But be carefull and check the boost, don't go over 2500mbar !!!
If this doesn't work, than there's a leak. Goodluck. Sorry for my Englisch..

Yes I think it's me .i've done a lot with G60's ... Blue Golf mk1


BR,
Jeroen

Thank you !!
Indeed my boost is too low, and i can really feel the loss of performance.
Btw, i was asking myself too for the N75 duty, why it doesnt go higher to try to reach requested boost ? I have an ABT remap from stock, and the car was running fine for years, but now i am a little disapointed. FYI, i have a n75 F version (replaced to new already, but did not cured). Maybe should i look for a leak in a first time ?? any idea on how to do it ?

thanks so much !

Marc