[Justanothersept]

I've found the reason for the jerking which could be the maf sensor. I've cleaned it and no success. Once unplugged, engine light pops up but runs smoothly. Cleared the engine light and runs fine. So my question is could I buy a sensor for a 2004-2009 or does it have to be a new giulietta face 2010> (

...old giulietta cost less and im on a tight budget.

My giulietta is the newish face 2011 1.6 diesel.

 

[Justanothersept]

Both would be brand new.

 

[symon]

The Giulietta didn't start in production until 2010, so I am not sure how you are going to get a MAF for a 2004-2009 one?

Unless you mean from a 156/147 etc?

If the part number is different it is highly likely that it won't work properly. They may be calibrated differently, have different connectors, or are main tube might be a different size etc...

 

[Justanothersept]

Ok thanks for that info. Does a maf have an affect on the stop start? Cause on the website it state "Vehicle Equipment :for vehicles without start-stop function"

http://m.buycarparts.co.uk/bosch/678529

On other website it doesn't state it but it is the same brand and part number

 

[symon]

As far as I know all Giuliettas have stop start function.

The MAF shouldn't have a direct affect, but if it has failed badly enough for the engine to go into limp mode (warning light on dash) then the stop start and DNA will become disabled.

 

[Nickhoughton567]

As far as I know all Giuliettas have stop start function.



The MAF shouldn't have a direct affect, but if it has failed badly enough for the engine to go into limp mode (warning light on dash) then the stop start and DNA will become disabled.

GQV doesn't have S&S

 

[Cuore_Sportivo_155]

Or, the MAF is working properly, and is reporting what it measures to the ECM...

Check for boost leaks first.

 

[Justanothersept]

Surely if there was a leak the car would jerk still if the maf sensor was turned off right ?

 

[symon]

Not necessarily.

With the MAF unplugged the car will go into limp mode. This is a "safe" set of parameters which ignores the readings of most of the sensors and allows the car to run in a reduced performance mode. Because the MAF meters air and it is being ignored in limp mode the air leak (if you have one) no longer has an effect.

If you have the MAF plugged in and you have a leak or air, the MAF reading will be incorrect, but the car doesn't realise it is incorrect hence the jerky performance.

It might also be that you have a fault elsewhere, and by unplugging the MAF and putting the car into limp mode makes the car ignore the reading from the faulty sensor (whichever that might be)

Hope that makes sense?