MAF/Air flow meter...

[swiftkid 1]

My apologies for starting another thread as there are plenty out there but i havn't found my answer exactly and im hoping to get a straight answer.

 

Basically i've been running my VR (latest of late spec) for about a month now and it seems to like to judder slightly when cruising at around 2.5-3k, now my first thoughts were ht leads, coil or maf. Reading up on things, it appears the MAF could and most probably is a problem so i unplugged it while it was on and nothing happened which i thought straight away, its a bit dead. Read more into it and apparently the later MAF's won't change anything if you unplug on idle but will when you rev it up, which i did and still no change in the running. This then lead me to believe that the ECU has adapted to the MAF not working.

 

So i thought one last ditched attempt would be to reset the ecu, which again made no difference. Now am i right in thinking that the MAF has in fact, died or is my information incorrect and the there is another way to check if the MAF has died?

[dr_mat 0]

So i thought one last ditched attempt would be to reset the ecu, which again made no difference. Now am i right in thinking that the MAF has in fact, died or is my information incorrect and the there is another way to check if the MAF has died?

 

Plug in the diags to your ECU, if the MAF has been bypassed you will get an error code. Note that if you allow the engine long enough without the MAF plugged in it will adapt and you won't notice much difference in running. You need to unplug the MAF, then pretty much straight away hit the throttle quite hard - it should stutter big style with a lean cut because it's got no MAF input. If it doesn't chances are your ECU had already decided the MAF was dead.

 

But I say again - the ONE TRUE way to know is to read the error codes. That's what this OBD (on-board-diags) stuff is all about. Save time and effort, ask the computer.

 

FWIW your MAF is *probably* dead, and a quick way to check is to pick up another one. There's usually plenty on ebay for sensible money. You run the risk of that being faulty too of course.. And if you have a late VR IIRC you can buy the same model MAF from GSF for about £60 because it's shared with a golf, or something like that..