MAF Question.

[quattroboy]

Hi Guys,

Quick question.

Can a MAF Sensor cause High Idling Problems?

I have a new ISV but keep getting Code 2231/VAG COM 0533.

My Vacuum Reading at idle is 17" - 18" HG. Is this about right?

The idle speed with fully hot engine is around 850/900 RPM but I believe that the parameters are based on 750rpm at idle with no load (No Aircon Compressor etc)

I am going to test my Intake System once I have Lees Pressure Test Kit.

I have no associated MAF DTC's and the car pulls like a train and overboosts as it should.

Anybody got any thoughts?

Cheers

Dave

[audiman]

Thats the right idle speed.

[quattroboy]

Thats the right idle speed.

Uhmm,

Thanks for the reply Tom.

So maybe the 2231 is indeed a Vacuum Leak or are those Vac HG readings okay.

I guess I will know more when I get my hands on the Pressure Test Kit.

Ta

Dave

[S2central.net]

Idle speed should be 780-820rpm

Vacuum at idle shoudl be -0.5bar.

BY the conversions here -

http://www.convert-me.com/en/convert/pressure

It seems you have too much vacuum so perhaps a wee leak alright.


Paul

[quattroboy]

Too Much Vacuum!

Thanks for the info Paul!

That's a good Conversion site btw!

Bl**dy Hell, I didn't know that you could have too much Vac.

I thought that my AAN was idling @ 17"HG and that this was too low..........the MityVac Manual indicates that between 16 & 20 was okay but I think I got 20" in my head as the norm when I connected the MityVac to my.......now don't laugh will you.....3.0 V6 Omega that registers bang on 20"

Roll on Pressure Testing Kits!!

If I do have a leak and fix it then hopefully the 2231 will go away but my original question on wether a dodgy MAF Sensor could throw a 2231 was because Gary Bray (Unicomsystems S4 Guy) said his disappeared when he had a (Very Expensive) new MAF fitted.

The mission continues.

Thanks for the input thus far.

Dave

Idle speed should be 780-820rpm

Vacuum at idle shoudl be -0.5bar.

BY the conversions here -

http://www.convert-me.com/en/convert/pressure

It seems you have too much vacuum so perhaps a wee leak alright.


Paul

[S2central.net]

It could also be a dud MAF... *some* MAF tests are on S2 Central...



Paul

[Mihnea]

17" of vacuum at idle is not too bad, 12-ish sounds like a leak.

too much vacuum would mean too little cam overlap, too high compression or **** knows what, but definitely not a leak...

Mihnea

[S2central.net]

A PCV / breather problem maybe would cause this as well...


Paul

[karlblues2]

A PCV / breather problem maybe would cause this as well...


Paul

What's a PCV?????
My vacuum often drops to 25-28 HG when backing off. At idle it's around 20? Is this ok?

[Mihnea]

Karl, 25-28" of vacuum on lift-off and 20 at idle sounds like a perfectly leak-free car.
The PCV is Positive Crank Ventilation, or breather system.

Mihnea

[karlblues2]

Karl, 25-28" of vacuum on lift-off and 20 at idle sounds like a perfectly leak-free car.
The PCV is Positive Crank Ventilation, or breather system.

Mihnea

Thanks Mihnea. I still can't understand why I can only get 15 psi on full boost now. I have checked hoses etc, reconned turbo, and still can't induce 'overboost' up to 19psi as I used to?
Anything else that could lose me 3-4psi?

[S2central.net]

Check your throttle switch is A) mechanically getting to full throttle. and B) when it does that the resistance is correct. Info on S2 Central - technical...

Also check your air and coolant temp sensors are in spec.

And the ambient pressure sender.

WGFV OK ?

Paul