MAF trouble or just hypochondria

Kernowcrispy

Active member
Joined
Nov 13, 2004
Location
Wellington
TDI
'97 Golf 1.9 TDi CL in Forest Green
Just thought I'd ask a really simple question ...

How much difference should there be with the MAF sensor connected and with it disconnected?

I've been troubled by poor MPG for a while and still can't find any reason. A friend has recently had to replace their MAF sensor on a Bora which made the world of difference to it so I thought I'd try to test mine to see if it works.

Firstly I put a metre on it whilst blowing air on the blade, there was some change in it's output but I've no idea how much there should be.

So I unplugged it to see what would happen and there was no noticeable change at idle. I took it out for a spin and there was definately less life in the engine and the turbo seemed non-existent, which is what I was expecting really. But what supprised me was that there wasn't that much of a drop in performance, it still revved OK although it took longer to get there and there wasn't any obvious smoke or any other indication that the engine was running rich/lean.

How much difference should there be?

How can you test the MAF to see whether it is working/calibrated correctly?

Many thanks

Crispy
 

Vin

Member
Joined
Aug 21, 2000
Location
Utah,USA
TDI
Jetta/2001/Silver
Any speed lost on an incline? My car had similar symptons you described. It was the MAF. Find someone with a VAG-COM. The VAG-COM should reveal some information on the MAF performance. I forgot which value you need to look at on the VAG-COM. It's field 001, 003 and 013...I don't remember the rest.
 
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