Disconnected MAF, ESP off??

[Gubien]

Hi everybody

I'm "investigation" the problem most of us have? Powerloss at about 3000-3500 rpm. So I wanted to find ou if it was the MAF sensor that where making trouble. So I disconnected the plug, but when I started the car, the ESP off lamp what lit? I would exspected the engine lamp to lit.

But but... drove home from work and it overall seemed okay, in the beginning it was a bit messy when i'd set off.
But the wierd thing... My fuel consumption is nomally at 8.5l/100 km due to the traffic and so on.... but this day it was 7.0l/100 km.

May'be my MAF sensor i "loco"?

And so far, I havent had the "power loss" at 3000-3500 yet...yet... even though I tried to provoke it...

 

[csd_19]

For some reason the Traction Control / ESP gets disabled when the MAF is unplugged, its normal so don't worry about that.

Your consumption will be slightly worse as the engine runs richer than normal, instead of using the MAF to work out how much air is coming in it uses the MAP sensor.

It could be the start of your MAF dying, do you have access to VAG-COM to check for any other fault codes?

 

[Gubien]

Hmmm...I dont quite understand it... the MAF is the big black tube. And into that is the MAF sensor? Does they have one job each?

 

[Gubien]

Ohh ... I forgot to mention....aefter driving for at bit with the nonnector off, the engine lamp is also lit, is that normal?

Now I have the ESP and Engine lamp lit.

 

[andycupra]

the maf is the pipe immediately after the filter. This has a sensor in it than measures the amount of air entering the engine and is one of the measurements used to calculate fuelling etc. Therefore, if its reading incorrectly then it can cause issues.

If you dissconnect the maf, the esp/traction control light will come up on the dash, - you will also find that you now have no traction control, i think this is because the maf readings are used as part of this system to calculate torque loadings.. blah blah blah...

The engine light does not normally come on, however there have been numerous occassions where it has, especially on ibizas.

From your comments am i to take it that your fuel consumption has improved since dissconnecting the maf?
With the maf dissconnected, it will run slightly richer than normal as its using different information and so runs with 'safer / richer' settings. Therefore fuel consumption would probably get slightly worse if you were to unplug a healthy maf.
If your fuel consumption has got better since dissconnecting the maf, then this would indicate that the maf had been reading incorrectly resulting in poor economy.

hope this helps.

If you plug the maf back in both lights may go out, really depends though, the engine light may need to reset. It may be that the running richer has put the engine light on.

 

[Gubien]

Ok, hmm..... I think I ****ed up ( I read somwhere in here that I could try to clean the MAF sensor by dipping it in isopropyl alcohol. Let it dry out and refit it again...but I serious failed.

But the car runs SO bad in idle I dont even wanne try driving it. Still, if I disconnect the MAF plug, it runs "OK". But I dont like to give it some beans when it's in "safe mode".

I guess I killed my MAF...

 

[icemancupra]

Very interesting thread. I have a mk4 ibiza cupra 1.8T. i currently have the EPS light on and the engine management light on also, fule consumption has not changed, but i have no ABS or traction control. So could this be a duff MAF?

 

[Gubien]

Had the opportunity to run vagcom on my car this evening.

16486 - Mass Air Flow Sensor (G70): Signal too Low.
(Could this be related to the time where I disconnected the MAF plug?)

17545 - Fuel Trim: Bank 1 (Add): System too Rich
(I guess this is related to the first error? MAF disconnected and then safe-mode=too rich??)

So my question is, the plug is back on the MAF, but that wont delete my errors?
So no I have to delete the error, and do a TBA?

The car runs very bad in idle...almost shivers and farts...lol

 

[DPJ]

You need to replace that MAF, Gubien.

Then, delete codes and do a TBA.

 

[Gubien]

Hmmm.... but I only need to get a new MAF sensor right? Not the whole package with MAF sensor and house??

 

[traumapat]

in the uk we replace the whole tube and sensor as an exchange unit at the dealers.. although you can get them elsewhere.

re the power loss..... mine has always suffered from an intermittant flat spot at about 2900-3000. only happens on part throttle.

the car has had new temp senders, mafs, 2 remaps,lamba, turbo conversion and it still occasionly happens.

it sounds like the mafs dead on yours and i hope it sorts it out. but i think the power loss/ flat spot is something else. im thinking of changing the dv to a diaphram as im starting to think its a dv thing.

 

[Gubien]

What happens if I clear the codes an do a TBA even though the MAF is dead?

I cant really get a new MAF today, so I have to give it a chance.

 

[Deleted member 20482]

any pics on where the maf sensor is?
i think my mates has done this no traction control and eng light on...

 

[traumapat]

What happens if I clear the codes an do a TBA even though the MAF is dead?

I cant really get a new MAF today, so I have to give it a chance.

it wont make a difference. be wary of running without the maf plugged in as youll run rich.

 

[DPJ]

any pics on where the maf sensor is?
i think my mates has done this no traction control and eng light on...

It's the sensor that's bolted to the right hand side of the airbox.

 

[Gubien]

I think I might have fixed it. Ran vagcom for errors again.
Had the same to errors again.

Fooled around in vagcom the noob I am. Couldnt figure out where to delete errors. LOL
Did a TBA anyway, but the engine still ran bad.

Found out where to clear for errors. Engine lamp disappeared. But had still the ESP lamp.
Read somewhere on the net that I just had to turn to ignition and back twice, and start the car. ESP lamp gone and the car runs normal now.

Started and stopped the engine to see if the error's will appear again. but they did not.

Now I just have to see, by driving around, if the "power loss" at 3000-3500 is gone...




Mick 18274:

http://www.galleri.meth.dk/uppic/85_big.jpg

It's underneath the plug at the left of the CDA logo