Unplugged maf questions

[DSDL-35-Cupra]

Hi all my cars boost seems to come and go when the throttle is floored. In each gear i'd say it boosts, disapears then boosts again not everytime but quite often when driving fast.

I've unplugged the maf and took it for a drive and it seems to boost ok now although it sometimes boosts ok anyway so need to drive it more tomoz, my questions are

As my traction control is now lit (was'nt before i unplugged it), does this mean TC is now off ?

Also i've been told the car use's a default setting when unplugged, as my car is mapped would this default setting effect boost levels or anything else ?

If it does seem to cure the problem being unplugged, am i ok to leave it un plugged until i get the spare money to replace.

thanks all Dom.

 

[DSDL-35-Cupra]

Just to add, while the car was ticking over i plugged in the maf and unplugged the maf and there was no change in engine tone between the two.

 

[W11TTX]

If I'm correct which I might not be.... I think the maff if goosed if u unplug it while the car is runnin and it's stays runnin it means it goosed and the ecu is controlling the air flow or along them lines... And if u unplug it and the at cuts out it means the maff is ok! Someone correct me if I'm wrong

 

[DSDL-35-Cupra]

Anyone ?

 

[LEE69]

You have to drive the car with the maf unplugged, not leave it on tickover.If no change chances are it's goosed.

 

[Muttley]

If you unplug the MAF then take it for a short drive and there is no change in the car's performance, or it gets better without the MAF, then it's a pretty clear indicator that the MAF signal is being ignored or is completely wrong. This might be a bad MAF, or it might be poor contact, so you could try cleaning the MAF contacts to see if it helps. Can't make things any worse from the sound of it.

The MAF is used to give the ECU information about the actual mass of air going into the engine, which allows it to set the fuel quantity precisely. If the signal is out of spec, the ECU ignores it and goes to a default fixed mass map (based on rpm x highest reasonable air density x cylinder capacity I would guess), which results in overfuelling and poor performance. Overfuelling is safer than under, but you don't want to be running with overfuelling for too long.

 

[LEE69]

No you will still be on the map, don't drive it for long unplugged.

 

[BEEFYGTI]

If you unplug the maf and the car boosts and runs better. Your maf is pooped. The traction light comes in when you have disconnected the maf but should go out after some time you have refitted the maf .

 

[motty225]

if the maf was faulty and the ecu was getting an incorrect reading would this cause the recirc valve to open or would it just have less performance?

 

[DSDL-35-Cupra]

I've been having slight running problems when in boost so plan to change the n75 valve a friend of mine came round last night and unplugged the maf as he had a very simalar problem on his gti turbo, took it for a quick spin last night and the car seems to run alot better while in boost like it was'nt struggling anymore but need to do a few more miles to make sure, just dont want to break the car driving with it unplugged. Thanks for the replie's all.

 

[DSDL-35-Cupra]

I it does seem to drive better, am i better plugging it in or leaving it unplugged until i get a replacement

 

[BEEFYGTI]

Don't drive it too long unplugged.