Irregular Idle (Hunting)
 

hi all,

My 2001 WRX has now got an irregular idle, it goes up to about 1500rpm then drops and almost cuts out.
Is this vacuum hoses?
Front O2 Sensor?

Any other ideas chaps?

Cheers

Simon

disconnect each in turn and see which has NO effect on engine ...that''ll be the culprit

i had a similar problem on my99 turbo,tried lots of things,it ended up being spark plugs which was a bit enoying but it solved the problem and car runs sweet now,if they are due then replace them for peace of mind if nothing else:thumb:

Cheers mate, if I find nothing else then spark plugs it is.

Sounds like front O2 sensor.

just looked at it, the wires look okay ish! where they come out of the sensor they look at little frayed, can these be repaired?

Depends how close to the sensor the damage is, if you need a new sensor I have one for sale at a very good price :thumb:

Hunting is normally a sign that the MAF sensor is playing up....... Start the engine and let it hunt then unplug the MAF, the car "Should" stall if the MAF is fine

Not wanting to hijack...but is this the MAF on my car:

http://i16.photobucket.com/albums/b3...sdicko/MAF.jpg

Yes thats your MAF

Cool, thanks mate. Will give it a go as well, as mine seems to be running a bit rough really, and idles weird occasionally.

Sometimes aftermarkets DV's can cause this problem too?? Just a thought!!

Hi Sem,
Yeah, I do think that's my problem to be honest! But will eliminate the MAF out of the equation.

so if the car doesnt stall when you unplug the maf but just idles funny, your maf is done? Is this correct?

What are the consequences of running the car like this?
Cheers..

Im just haveing time issues at the minute and havent had time to play, if my sensor is cream crakered how much for yours Chris?

Consequences could be a melted piston

if the car doesnt stall the ecu has learned to cope with the missing or wrong input

if in any doubt replace the maf, afterall its cheaper then a rebuild..

cheers for that...is there a possibilty it could cause bottom end failure as well?

Emailed you fella, im open to offers on it :thumb:

Yes.

If the MAF is knackered and is giving spurious readings it coud be giving a 'wrong' low rpm voltage at high rpm, fooling the ECU to dangerously underfuel. This could lead to terminal det, causing piston failure... or these extremely high-pressure det 'spikes' could hammer a big-end bearing shell into submission...