Performance problem

[Squale]

Hello,

I would to expose a problem which i'm experiencing with my S3.

The car : 2002, 225HP S3, ABT remap, stainless steel catback exhaust, silicone induction hose, cotton panel air filter in standard airbox, which was running very fine until the following pb occured:

When I log the boost with VAG COM, It never reach the target boost: i.e: 2300 mbar instead of 2500mbar for example between 3000 rpm and 4000 rpm.

Moreover, I especially feel a strong loss of power of the car. What is strange it is on motorway in 6th gear for example at stabilized speed, when I floor the gas pedal, the boost sometimes stagnates (I monitor with a gauge) and go suddendly to full boost (1.3-1.4bar, but not to the requested 1.5 bar).

Another phenomenon: sometimes when I release slightly the gas pedal , i feel the car pulling stronger !

I guess that all this must be dependent but I despair to find a solution now.

I replaced with new oem parts : dump valve (710N), the n249 and n75, MAF, as well as the suction pump (small Y of plastic) and PCV Valve under the intake manifold. I also inspected all the hoses and connections and pressurised the boost piping and do not find any leak.

If anyone has an idea, please do not hesitate.

Thx!

 

[DodgyDave]

From the age of the car have you tried the following:

1. Get some Carb Cleaner and clean out the airways from AFTER the MAF right through to the engine.

2. also use Carb Cleaner to clean out the throttle-body and then re-align it.

3. get some red-ex or whatever and run a load of that through with a tank of petrol, cleans out the fuel side of things.

Other thing it could be is the Engine Water Temp Sensor, that can cause performance issues but you usually get a CEL on the dash


Dave

 

[Squale]

From the age of the car have you tried the following:

1. Get some Carb Cleaner and clean out the airways from AFTER the MAF right through to the engine.

2. also use Carb Cleaner to clean out the throttle-body and then re-align it.

3. get some red-ex or whatever and run a load of that through with a tank of petrol, cleans out the fuel side of things.

Other thing it could be is the Engine Water Temp Sensor, that can cause performance issues but you usually get a CEL on the dash


Dave

Hi Dave,

The MAF is new, btw the piping is clean too.

I cleaned the throttle body sometimes ago but it didnt change the deal. (I've heard it was only for idle problems?)

Btw I was thinking about my fuelling too, which kind of product do you recommand me ? (brand)

Thanks,

Marc

 

[mrk]

i have the same problem with my ibiza and it turned out to be the fuel shut off valve, basically the car was cutting out the fuel supply when it wasnt nesessary hence the loss of boost and i know what you mean when you said you lift the pedal off and it pulls stronger

strange stuff isnt it

get some redex cleaner and put it in the next time you put a full tank of fuel in.

 

[Squale]

i have the same problem with my ibiza and it turned out to be the fuel shut off valve, basically the car was cutting out the fuel supply when it wasnt nesessary hence the loss of boost and i know what you mean when you said you lift the pedal off and it pulls stronger

strange stuff isnt it

get some redex cleaner and put it in the next time you put a full tank of fuel in.

That's very interesting !! Could you tell me what is this cut off valve and how did you see it was wrong ? btw do you have any picture of the valve ?

thank you !!!

 

[DodgyDave]

Hi Dave,

The MAF is new, btw the piping is clean too.

I cleaned the throttle body sometimes ago but it didnt change the deal. (I've heard it was only for idle problems?)

Btw I was thinking about my fuelling too, which kind of product do you recommand me ? (brand)

Thanks,

Marc

It could be a bit of crud stuck in the air side of things so althouth you've cleaned the TB you could have moved it somewhere else ???

Not sure on brands TBH, it's just getting burnt as it cleans so i just get whatever's in stock at the local car place as i'm in (just make sure it's for "UNLEADED PETROL CARS", easy mistake to do).

I run the petrol cleaners every 5k miles (between services) and try to clean the TB out a few times a year - i notice the difference after it's done


Dave

 

[DPJ]

Could you give us logs of the following:
003 and 020
115 and 031
118 and 032

Power runs full throttle in 4th.

That will help us diagnose your problem. Threre's a lot of guessing otherwise...

 

[f1btn]

Sounds to me like it could just need a throttle body allignment you can do it in vag-com engine controller/basic setting/block 060/adaption run.

 

[Romeoisgraham]

From the age of the car have you tried the following:

1. Get some Carb Cleaner and clean out the airways from AFTER the MAF right through to the engine.

2. also use Carb Cleaner to clean out the throttle-body and then re-align it.

3. get some red-ex or whatever and run a load of that through with a tank of petrol, cleans out the fuel side of things.

Other thing it could be is the Engine Water Temp Sensor, that can cause performance issues but you usually get a CEL on the dash


Dave

Cheers Dodgy Dave.................I too was experiancing some slow 0-60 but bought redex as you have suggested and damm. Its propper quick again. I love you dodgy dave.

 

[Squale]

Could you give us logs of the following:
003 and 020
115 and 031
118 and 032

Power runs full throttle in 4th.

That will help us diagnose your problem. Threre's a lot of guessing otherwise...

Hi !
I just did the logs, here they are :

Thursday 11 October 2007 23:31:19
8N0 906 018 BH 1.8L R4/5VT G 0001

Group A: '003 Group B: '020
Engine RPM Air Mass Flow Throttle Opening Ign. Timing Cyl #1 Cyl #2 Cyl #3 Cyl #4
TIME TIME
Marker STAMP /min g/s % ｰBTDC STAMP CF CF CF CF
0.02 2840 28.31 16.1 30.8 0.32 0.0 0.0 0.0 0.0
0.62 2840 27.56 15.7 30.8 0.92 0.0 0.0 0.0 0.0
1.22 2840 26.50 15.3 30.8 1.52 0.0 0.0 0.0 0.0
1.82 2880 24.36 14.5 31.5 2.12 0.0 0.0 0.0 0.0
2.43 2880 24.72 14.5 31.5 2.73 0.0 0.0 0.0 0.0
3.03 2880 24.58 14.1 32.3 3.34 0.0 0.0 0.0 0.0
3.63 2880 23.72 13.7 32.3 3.93 0.0 0.0 0.0 0.0
4.24 2880 30.69 16.9 30.0 4.53 0.0 0.0 0.0 0.0
4.84 2960 68.72 100.0 22.5 5.14 0.0 0.0 0.0 0.0
5.44 3080 107.64 100.0 10.5 5.74 0.0 0.0 0.0 0.0
6.04 3280 121.28 99.6 7.5 6.36 0.0 0.0 0.0 0.0
6.65 3560 126.78 100.0 13.5 6.95 0.0 0.0 0.0 3.0
7.26 3760 137.11 100.0 13.5 7.55 0.0 0.0 0.0 3.0
7.86 3960 140.86 100.0 13.5 8.16 0.0 0.0 0.0 3.0
8.46 4200 147.69 100.0 9.0 8.76 0.0 0.0 0.0 3.0
9.06 4400 154.61 100.0 9.8 9.36 0.0 0.0 0.0 3.0
9.66 4640 156.86 100.0 8.3 9.96 0.0 0.0 0.0 2.3
10.28 4800 162.25 100.0 14.3 10.57 0.0 0.0 3.0 2.3
10.87 5040 167.42 100.0 16.5 11.17 3.0 3.0 3.0 2.3
11.47 5200 168.61 100.0 14.3 11.78 3.0 3.0 3.0 5.3
12.08 5400 176.44 100.0 10.5 12.39 3.0 6.0 6.0 5.3
12.68 5560 182.61 100.0 14.3 12.98 2.3 6.0 6.0 5.3
13.29 5720 183.86 100.0 14.3 13.60 2.3 6.0 6.0 5.3
13.89 5880 188.06 100.0 15.0 14.19 5.3 8.3 5.3 4.5
14.49 6040 186.83 99.6 15.0 14.79 5.3 8.3 8.3 4.5
15.10 6160 181.11 99.6 15.0 15.41 5.3 8.3 8.3 4.5
15.71 6280 177.42 100.0 15.8 16.00 4.5 7.5 8.3 3.8
16.31 6400 168.33 100.0 17.3 16.60 4.5 7.5 7.5 3.8
16.91 6480 171.47 100.0 18.0 17.21 4.5 7.5 7.5 3.8
17.52 6600 169.47 100.0 18.8 17.81 3.8 7.5 7.5 6.8
18.11 6680 171.47 100.0 18.0 18.42 3.8 6.8 7.5 6.8
18.73 6760 171.97 99.6 19.5 19.03 3.8 6.8 6.8 6.8
19.33 6800 171.61 96.5 6.8 19.63 0.0 0.0 0.0 0.0
19.92 6760 12.75 8.6 10.5 20.23 0.0 0.0 0.0 0.0
20.53 6600 14.36 9.4 9.8 20.83 0.0 0.0 0.0 0.0
21.13 6120 13.75 9.8 7.5 21.43 0.0 0.0 0.0 0.0


Thursday 11 October 2007 23:35:15
8N0 906 018 BH 1.8L R4/5VT G 0001

Group A: '115 Group B: '031
Engine Speed Load Cmd Pressure Press @ Intercool O2S1 Voltage O2S2 Voltage Bin. Bits Bin. Bits
TIME TIME
Marker STAMP /min % mbar mbar STAMP
0.02 2040 31.6 990.0 1010.0 0.30 0.984 0.992
0.60 2040 57.1 1200.0 1000.0 0.90 1.000 0.992
1.20 2120 91.0 2050.0 1120.0 1.51 0.984 0.969
1.80 2240 109.8 2290.0 1320.0 2.10 0.953 0.953
2.41 2360 132.3 2450.0 1570.0 2.71 0.953 0.953
3.03 2560 156.4 2550.0 1870.0 3.32 0.961 0.953
3.62 2760 176.7 2550.0 2180.0 3.93 0.953 0.953
4.22 3000 185.7 2550.0 2280.0 4.52 0.953 0.953
4.83 3240 185.7 2550.0 2270.0 5.13 0.945 0.953
5.43 3520 185.7 2550.0 2270.0 5.73 0.945 0.953
6.03 3720 185.7 2550.0 2300.0 6.33 0.930 0.953
6.64 3960 182.7 2550.0 2220.0 6.96 0.953 0.953
7.24 4240 182.7 2540.0 2190.0 7.54 0.922 0.953
7.84 4440 181.2 2500.0 2180.0 8.14 0.953 0.953
8.45 4640 179.7 2420.0 2130.0 8.75 0.938 0.953
9.05 4880 177.4 2370.0 2120.0 9.35 0.953 0.953
9.65 5040 173.7 2350.0 2070.0 9.96 0.961 0.953
10.26 5240 172.2 2350.0 2080.0 10.56 0.945 0.953
10.86 5400 170.7 2350.0 2050.0 11.16 0.961 0.953
11.47 5560 171.4 2280.0 2080.0 11.76 0.961 0.953
12.07 5680 176.7 2160.0 2020.0 12.37 0.899 0.906
12.67 5840 164.7 2110.0 1990.0 12.97 0.836 0.836
13.27 5960 160.9 2030.0 1990.0 13.57 0.789 0.805
13.88 6120 162.4 1970.0 1860.0 14.18 0.782 0.821
14.48 6240 156.4 1920.0 1850.0 14.78 0.821 0.844
15.08 6320 152.6 1890.0 1870.0 15.38 0.867 0.852
15.70 6440 147.4 1870.0 1830.0 16.01 0.867 0.867
16.29 6560 136.8 1840.0 1810.0 16.59 0.867 0.867
16.89 6600 140.6 1850.0 1800.0 17.19 0.844 0.852
17.51 6640 130.1 990.0 1680.0 17.80 0.750 0.860
18.10 6440 12.8 990.0 1230.0 18.40 0.758 0.813
18.70 5920 12.0 990.0 1090.0 19.00 1.991 1.047
19.30 5400 12.0 990.0 1050.0 19.61 1.991 1.047
19.91 4960 12.8 990.0 1020.0 20.20 1.991 1.047
20.51 4720 12.0 990.0 1020.0 20.81 1.991 1.047
21.11 4640 12.0 990.0 1010.0 21.42 1.991 1.047
21.72 4520 12.0 990.0 1010.0 22.03 1.991 1.047
22.32 4440 12.0 990.0 1020.0 22.62 1.991 1.047

Thursday 11 October 2007 23:38:17
8N0 906 018 BH 1.8L R4/5VT G 0001

Group A: '118 Group B: '032
Engine Speed Intake Temp N75 Duty Cycle Press @ Intercool Idle Value Part Throttle Value
TIME TIME
Marker STAMP /min ｰC % mbar STAMP % %
0.02 2080 26.0 0.0 1230.0 0.30 0.0 -0.8
1.82 1960 27.0 0.0 1010.0 1.52 0.0 -0.8
2.42 1880 29.0 0.0 1010.0 2.11 0.0 -0.8
3.02 1920 29.0 84.3 1010.0 2.73 0.0 -0.8
3.63 2000 27.0 84.3 1160.0 3.33 0.0 -0.8
4.23 2120 24.0 84.3 1300.0 3.93 0.0 -1.6
4.84 2240 23.0 84.3 1470.0 4.54 0.0 -2.3
5.43 2400 21.0 84.3 1690.0 5.15 0.0 -2.3
6.04 2600 21.0 84.3 1970.0 5.74 0.0 -2.3
6.64 2800 20.0 84.3 2240.0 6.35 0.0 -2.3
7.25 3080 19.0 84.3 2310.0 6.95 0.0 -2.3
7.85 3280 19.0 84.3 2290.0 7.55 0.0 -2.3
8.46 3560 19.0 84.3 2280.0 8.17 0.0 -2.3
9.09 3800 20.0 84.3 2260.0 8.76 0.0 -2.3
9.66 4000 20.0 84.3 2240.0 9.36 0.0 -2.3
10.27 4240 21.0 84.3 2220.0 9.97 0.0 -2.3
10.87 4440 21.0 84.3 2190.0 10.57 0.0 -2.3
11.58 4680 23.0 84.3 2130.0 11.19 0.0 -2.3
12.19 4880 24.0 84.3 2110.0 11.88 0.0 -2.3
12.78 5080 24.0 84.3 2060.0 12.48 0.0 -2.3
13.38 5280 25.0 84.3 2070.0 13.09 0.0 -2.3
13.99 5440 26.0 84.3 2030.0 13.69 0.0 -2.3
14.59 5600 27.0 84.3 2030.0 14.29 0.0 -2.3
15.21 5760 29.0 84.3 2010.0 14.89 0.0 -2.3
15.80 5920 30.0 84.3 1990.0 15.51 0.0 -2.3
16.40 6040 30.0 78.4 1900.0 16.10 0.0 -2.3
17.02 6160 31.0 78.8 1910.0 16.70 0.0 -2.3
17.61 6320 32.0 76.1 1890.0 17.31 0.0 -2.3
18.21 6400 33.0 75.3 1860.0 17.92 0.0 -2.3
18.82 6520 33.0 72.9 1780.0 18.52 0.0 -2.3
19.42 6640 34.0 71.0 1740.0 19.13 0.0 -2.3
20.03 6720 34.0 70.6 1760.0 19.73 0.0 -2.3
20.64 6680 33.0 0.0 1380.0 20.33 0.0 -2.3
21.23 6360 33.0 0.0 1120.0 20.93 0.0 -0.8
21.83 5760 33.0 0.0 1060.0 21.53 0.0 -0.8
22.44 5240 33.0 0.0 1040.0 22.13 0.0 -0.8
23.04 5080 33.0 0.0 1020.0 22.74 0.0 -0.8
23.64 5000 33.0 0.0 1010.0 23.34 0.0 -0.8
24.25 4880 33.0 0.0 1010.0 23.94 0.0 -0.8
24.85 4800 33.0 0.0 1010.0 24.55 0.0 -0.8

I hope it will help, btw just after the logs I checked again my fault codes and found this one which was not possible to erase directly, only after some mins of engine cool down I managed to erase it :

1 Fault Found:
17863 - Exhaust Gas Temp Sensor 1 (G235): Implausible Signal
P1455 - 35-10 - - - Intermittent

I never got this one before.

Thx !!

 

[mrk]

its showed up on vag-com but i have no pics

probs wouldnt be hard to find any pics right enough

 

[DPJ]

Yes, I'd take at stab at a sensor fault making the car run rich.
8.3 Corrections factors a bit high.
The value in the last column of 032 (Negative running rich) changes with rpm. It shouldn't.

Also actual boost is strugling to meet requested.

 

[Squale]

Yes, I'd take at stab at a sensor fault making the car run rich.
8.3 Corrections factors a bit high.
The value in the last column of 032 (Negative running rich) changes with rpm. It shouldn't.

Also actual boost is strugling to meet requested.

Could you let me know more about CF, what is this 8.3 meaning ? In fact what CF represents ?

What do you recommand me to do then, is it possible that this EGT sensor be the source of my prob ? Or could it be a lambda one ?

thx
Marc

 

[f1btn]

Could you let me know more about CF, what is this 8.3 meaning ? In fact what CF represents ?

What do you recommand me to do then, is it possible that this EGT sensor be the source of my prob ? Or could it be a lambda one ?

thx
Marc

Cf is correction factor of the timing so its pulling 8.3deg of timing outta the map this only occurs when the car pulling a lot of boost which yours isnt or the fueling running lean or the charge temps are too high!
sounds like it needs to be checked by a pro near where u live!

 

[Squale]

Cf is correction factor of the timing so its pulling 8.3deg of timing outta the map this only occurs when the car pulling a lot of boost which yours isnt or the fueling running lean or the charge temps are too high!
sounds like it needs to be checked by a pro near where u live!

Understood, but don't you think the EGT error code I got could be the source ?