hi,

on my 1993 wrx the idle is fine no fluctuation etc but every about 3 seconds it feels like it misses a beat, its difficult to describe the revs stay still so dont think its idle valve or maf but stuck on what it can be.

apart from that there is no other missfire at all through the gears, there used to be a flat spot about 4k where is thinks for about 1/2 second then goes but that seems to have gone now.

anyone had this idle missing problem ??

cheers

J

 

Idle problems are often the lambda sensor (oxygen sensor) in the exhaust.
Dont sue if im wrong.
Yours does however seem like an occasional missfire.

 

spark plugs or coil packs may need changing

 

Did you manage to solve this as mine is now doing exactly the same (no flat spots or hesitation whilst driving, just 'missing a beat' or 'shuddering' every couple of seconds when idling) This has only started after changing the plugs and filter and not sure whats causing it?

 

Seems like loads of people having this problem, mine too, try the coils as that might explain the flat spot. Look for cracks in the plastic casing

 

My wifes S splate had the same problem - it was the Lamda sensor, replaced it and Robert is your Dad's brother...


Cheers

Paul