Testing MAF/ sensor

[Dezeze]

Right guys, just wandering, when testing MAF sensor,mdo u just unplug the switch at the top or actually remove the full MAF from the air filter box/ silicone housing?
Cheers, trying to solve my lack of turbo issues!

 

[seatcupramad23]

just unplug it mate

 

[Dezeze]

Cheers bud, let the games begin lol

 

[mrdavies]

if it needs cleaning really simple too

 

[Dezeze]

Right, just took the car out, unplugged the sensor at the top of the MAF unit, and the car performed like it had a Definately lack of power. Turbo spooled to about 0.5 bar max. I noticed there was nil dark smoke!
Re plugged MAF sensor, car performed a lot better, however, still not pressurising to about 3000 rpm, in which it's all at once! And lthe smoke returns!
Is this a knackered MAF (bear in my I have the mechanical expertise of Jeremy Clarksons subtlety!)
I have one set aside. At Eurocarparts, but don't want to fit it if it's not needed!

 

[seatcupramad23]

have you scanned the car mate ?

 

[Dezeze]

The garage said no fault codes to report yesterday. Don't think it was Vagcom though , would that make much difference?
Just the black smoke/ fitted , not fitted/ no black smoke equations confusing me!

 

[rsmith]

What g/s does the MAF read at idle, should be between 2-4 g/s, it might be a tired MAF over a faulty one.Also if you suspect a dodgy maf your fuelling will be off you can check these values in vagcom.

 

[Dezeze]

It's on the Vagcom next week! Just going to take it easy till then(looking fwd to a 600 mile trek this weekend)
Hopefully Seat won't rob me blind for the pleasure!

 

[rk696]

You would be better measuring the g/s reding at WOT, and plotting it on a graph to make sure it is a nice smooth curve. Sometimes it will read OK at idle and low speeds, but as the airflow inceases, it gets less accurate.

As rsmith siad, check the lambda values in vagcom to check what the mixture is like. It may also be worth logging the requested vs actual boost values.

 

[Dezeze]

Thanks for all the advice gents, it's very much appreciated! Learning a lot on this forum, very insightful and polite forum members!
The 600 mile round trip never happened(well not in the Leon, the wife's Lupo yes!)
Limp/ lame mode twice in 8 miles!

 

[joehirth]

Black smoke normally indicates running rich. Unplugging MAF can hide other problems. I would get the new one on there anyway cars seem to perform better with a new MAF. Make sure it's Bosch too!