Jump to content

Mi s3 no tira lo que debería, me ayudáis?


JoanLau//S3
 Share

Recommended Posts

Parece que incluso va mas fino que antes...

Cuando pueda cambiare la primera y el coche quedara mejor todavia!!!

 

No me cantes victoria que ya sabemos que a veces las cosas no son lo que parecen!!!!!!!... :harhar:

 

Pero bueno, si notas una notoria mejoria, pues podemos confiar que hemos dado con la solución... :thumbsup:

 

Ya contarás como va funcionando el coche...

 

felicidades y un saludo

Link to comment
Share on other sites


  • Replies 109
  • Created
  • Last Reply

Top Posters In This Topic

Ufff pero eso vale muuuuchooooo!! Jejejje

 

No te creas, en Madrid hay un especialista que te los vacía y te los hace de acero inoxidable por 250 pavos/unidad... que luego ya es eterno, si se atasca como pasa siempre, se saca, se limpia y "paentro" otra vez como nuevo... yo cuando empiece a oler a huevo podrido, ya sabes lo que voy a hacerle... a ver si me acuerdo como demonios se llamaba, que esa es otra ajajajjaja

Link to comment
Share on other sites

Mie***... otra vez en limp mode tras 100km de autopista, no hay luz de averia todavia pero me esta cansando, esto se me esta haciendo mas largo que el señor de los anillos!

 

Pues vaya, lo miramos mañana a ver que sale. :thumbsup:

Link to comment
Share on other sites

Joan, leyendo en foros ingleses todo el mundo indica que es un problema de que la mezcla va muy pobre, las soluciones que aportan son:

 

Problema con la N75

Problema com las lambdas

Problema con el MAF

Bujias o bobinas en mal estado

Inyectores sucios

Alguna toma de aire en el circuito de vacio

 

A la gente que le da ese error también le limita la presión de soplado a 0,4 es normal.

 

Leyendo mas me encuentro esto:

 

The value of 101.81 g/s air mass drawn in may flag my MAF as being the culprit. Ross-tech suggests this value should be about 80% of the horsepower at redline and since it reads also as (Mult) it should point to the MAF. So, presumably, I should be seeing around 136 g/s drawn through the MAF on my bone stock 2001 Audi A4 1.8T B5 AWM. Over the past couple of months I have felt some horsepower loss and this should be evident of that. I wanted to get any suggestions before assuming its the MAF and not one of the other suggestions made by the manual.

 

En los log que hicimos llegaba por los pelos a 100g/s y aquí indica que un 1.8T de un A4 (con un k03) debería llegar a medir 136g/s, se podría deducir que el MAF esta sucio.

 

También me encuentro esta extensa explicación de como se gestiona la mezcla de combustible/aire:

 

Some of the most common fault codes (DTC's) pertain to fuel trim. Here is an explanation of fuel trim and what it does for us.

The ECU controls Air/Fuel mixture in order to maintain power, efficiency, and emissions. A/F is expressed as either a ratio (14.7:1 for example) or as a Lambda value. With iso-octane ("ideal" gasoline), Lambda of 1.0 is equal to 14.7:1 A/F. This is known as "Stoichiometric", a condition where there is a perfect balance between oxygen molecules and the various hydrogen and carbon based molecules in petroleum. With the oxygenated gasoline that most of us use, actual A/F ratio of 15:1 is closer to stoichiometric.

 

If Lambda is greater than 1.0, then there is a surplus of air and the engine is running lean. If Lambda is less than 1.0, then there is a surplus of fuel and the engine is running rich. It should be noted that the ratios are mass-based, not volume-based.

 

So, why don't we always run at 1.0 all the time? Well, we do MOST of the time. At cruise and idle, mixture is held tightly to 1.0 to keep the catalytic convertor at optimal efficiency, so the emissions are minimized. However, when we need acceleration, the mixture gets richer. Why? Maximum power is made between 0.85 to 0.95 Lambda (12.5 to 14.0 A/F with iso-octane). So, under acceleration, mixtures get richer. Sometimes you want to get even richer under acceleration to keep detonation (pre-ignition of the mixture from excess cylinder temperatures) away. The 1.8T, for example, has a relatively high compression ratio for a turbocharged engine, which especially under lots of boost, is very succeptible to detonation).

 

So, now that we know that the ECU wants to be able to control the A/F ratio. It has a prescribed set of values (maps) for a given RPM, Load, etc. So, the ECU tells the injectors to pulse for exactly XX.X milliseconds and that SHOULD get us the proper A/F ratio that we want. Well, if you tell an employee to go do something, you want to make sure they actually did it, right? The ECU has some snitches (the front O2 sensor and the MAF, for the most part) that will report back whether or not the desired mixture has been attained. The rear O2 sensor is used mostly to monitor the condition of the catalytic convertor, although in some applications it also contributes to trim information.

 

Based on feedback from the snitches, the ECU learns to apply a correction factor to its commands to the fuel injectors. If you know that your employees take longer than the standard allotted time to do a specified job, you will need to adjust for that in your planning (injectors are in a union, so it is tough to fire them ). The learned values go between the maps in the ECU's Flash ROM (the "chip") and the signal to the fuel injectors. These learned compensations are known as "trim". So, when you see "trim", it means "compensation".

 

"Add" means additive trim, which is addressing an imbalance at idle. When the ECU is using additive trim, it is telling the injectors to stay open a fixed amount longer or shorter. The malfunction (e.g. vacuum leak) becomes less significant as RPM increase. For additive adaptation values, the injection timing is changed by a fixed amount. This value is not dependent on the basic injection timing.

 

"Mult" mean multiplicative trim, which is addressing an imbalance at all engine speeds. The malfunction (e.g. clogged injector) becomes more severe at increased RPM. For multiplicative adaptation values, there is a percentage change in injection timing. This change is dependent on the basic injection timing.

 

You can check your current state of trim by using VAG-COM or equivalent to look in Group 032 in your engine measuring blocks. The first two fields will have percentages. The first field tells the fuel trim at idle (Additive). The second field tells the fuel trim at elevated engine speeds (Multiplicative). Negative values indicate that the engine is running too rich and oxygen sensor control is therefore making it more lean by reducing the amount of time that the injectors are open. Positive values indicate that the engine is running too lean and oxygen sensor control is therefore making it richer by increasing the amount of time that the injectors are open.

 

It is totally normal for both the first and second fields to be something other than zero. In fact, zeros indicate either you just cleared codes (which will reset fuel trim values) or something isn't working properly. If values get too far away from zero, it will cause a DTC (fault code) and can set off the MIL (commonly referred to as the Check Engine Light, or CEL).

 

Specifications for normal operation are usually somewhere near +/- 10%.

In general, an out-of-spec value in the first field (Additive) indicates a vacuum leak since it is mostly present at idle, when vacuum is highest. An out-of-spec value in the second field (Multiplicative) indicates a fault at higher RPM, and may point to a faulty MAF.

 

Here's a good sanity check for the status of your MAF. Do a full-throttle run all the way to redline in a single gear (second works fine). Group 002 usually shows air mass in g/s. Your peak airflow should be roughly 0.80 times your horsepower. So, if you have a stock 150 hp 1.8T, expect around 120 g/s. If you have a 201 hp 24V VR6, expect around 160 g/s. If you see significantly less than that, you MAF may be on the way out. This still works if you are chipped, but "race" programs may make more power through timing, rather than airflow. Therefore, take all readings with a grain of salt.

 

En algunos casos llegan a hablar del regulador de presión o de la bomba de gasolina, pero creo que en el tuyo no sea eso.

 

Seguimos hablando a ver si damos con la solución.

 

Un saludo.

Link to comment
Share on other sites

Gran aporte compañero...

Esta semana revisare las bugias, cambiare el filtro de gasolina y le pondre un limpiainyectores.

Aparte limpiare mas a fondo el caudalimetro.

Pobre coche, lo compre con gripe y anginas!

Gracias x todo!!

 

Tu tranquilo, empieza por lo mas básico , veras como al final se soluciona.

 

La gripe se cura con antibiotico, y las anginas operando :roll1:

 

Un saludo.

Link to comment
Share on other sites

Buenas

 

Ahora, aunque no falle el coche, pásale el vagcom para ver cómo funcina la sonda que marcaba vaor fijo, a ver si sigue haciendo lo mismo.

 

Por cierto, lo de limpiar el caudalímetro no es una solución... Los caudalímetros "se gastan..." aunque no lo parezca y aunque lo limpies, al principio parece que va bien, pero a los pocos dias vueleve a ir mal... si estuvieras en mis clases te explicaba el porqué pasa esto...jajaja...

 

Un saludo y suerte...

Link to comment
Share on other sites

Buenas

 

Ahora, aunque no falle el coche, pásale el vagcom para ver cómo funcina la sonda que marcaba vaor fijo, a ver si sigue haciendo lo mismo.

 

Por cierto, lo de limpiar el caudalímetro no es una solución... Los caudalímetros "se gastan..." aunque no lo parezca y aunque lo limpies, al principio parece que va bien, pero a los pocos dias vueleve a ir mal... si estuvieras en mis clases te explicaba el porqué pasa esto...jajaja...

 

Un saludo y suerte...

 

 

Cuando eso avisa que yo me apunto a una de tus clases que cuando yo estudie mecánica mi coche aun estaba en la primera fase de producción, lo mas que teníamos era motores de bx, lancia delta, renault 21...

 

Un saludo.

Link to comment
Share on other sites

Buenas

 

Ahora, aunque no falle el coche, pásale el vagcom para ver cómo funcina la sonda que marcaba vaor fijo, a ver si sigue haciendo lo mismo.

 

Por cierto, lo de limpiar el caudalímetro no es una solución... Los caudalímetros "se gastan..." aunque no lo parezca y aunque lo limpies, al principio parece que va bien, pero a los pocos dias vueleve a ir mal... si estuvieras en mis clases te explicaba el porqué pasa esto...jajaja...

 

Un saludo y suerte...

 

 

Cuando eso avisa que yo me apunto a una de tus clases que cuando yo estudie mecánica mi coche aun estaba en la primera fase de producción, lo mas que teníamos era motores de bx, lancia delta, renault 21...

 

Un saludo.

 

Vale, cuando toque explicar componentes de inyección te aviso...jejeje...

 

El caso es que se gastan porque el aire, que contiene inpurezas, pasa por la plaquita de medición del MAF y hace un efecto "lija" en dicha plaquita desgastándola y modificando el espesor de la plaquita. Eso hace que, al darle el mismo valor de tensión por parte de la UC para mantener la temperatura de referencia, ésta sea ligeramente superior, haciendo que la UC se crea que entra menos aire del real, inyectando menos de la cuenta y faltando enti nces potencia al motor....

 

Así a grandes rasgos es lo que pasa con los MAF y del porqué provocan una falta de potencia en el motor....

 

Un saludo

Link to comment
Share on other sites

Repasemos:

N75 nueva

N249 Nueva

Bujias Bosch platino nuevas

Lambda 2 Nueva

Bobinas limpias

Conectores de lambda limpios

Limpiainyectores puesto con reserva bajo minimos

Filtro de gasolina que no se cambio en la vida, nuevo.

Y como siempre, dura 100km y otra vez en limp...

Me queda ver el valor del Maf y la sonda 1 nueva...

Sino ya...

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.





×
×
  • Create New...