My MY99 Impreza turbo had been idling badly. Hunting thru 600 to 1000 RPM.
Was due it's service so took to the dealer... no names but they're based in Ayr "Not sure what was causing it sir but there is an old fault code in the memory for the crank sensor...we've reset the computer... the car will be back soon they are road testing it."
Got the car round the corner and idling was still a bit hesistant had to be back up in Glasgow so didn't have time to go right back.
Anyway problem is now much worse, twice it's cut out completely as I have been too slow to blip the throttle to bring up the revs.
So I am facing another trip doon to Ayr.
Could someone give me some idea as to likely causes of the poor idling?
Really p&sses me off when the so called experts can't diagnose a fault when their computer doesn't help them out and worse when they return the car with the fault they were supposed to fix.
Could failing crank sensor cause poor idling...it was replaced a wee while back then the car just didn't start!
Cheers Doug

 

common fault is the MAF sensor, and could well cause the issues you are describing................

alyn

 

hi m8, Subaru told me,when i was worried about the maf, that what you have described is a failing maf sensor,ie-hunting,stalling,almost cutting out.

hope this helps.

Lee

 

maf
air leak
knackerd plugs
lambda

would be the order that i personaly would check

 

with the engine idling unplug the maf, if the car stalls this would point more towards the maf. (to unplug the maf - sorry if its a teaching granny moment! unplug the jack plug on the back of the plastic tube thats bolted to the air box) this will bring the check engine light on (cel) nowt to worry about and should go out once reconnected

stevie

 

Thanks for the quick replies
The MAF was what I'd been thinking
Still can't understand why the garage would return the car without at least tracing a fault!!!!????

 

that was what happened to me with my local friendly subaru dealer. the car was only making 6 psi boost, they said it was proberly something to do with the dump valve (vta) maybe, but still took best part of 20 bucks off me for the privilage. it would of took me (no mech) 5 minutes to put a recirc off a forcourt car onto mine then you would know. took it to well lane who, after a bit of fiddling said it was proberly the knock sensor, which it was. i no longer go to my local friendly subaru dealer!

stevie

 

Get the facts right please It's if your engine doesn't stall when unplugging the MAF that indicates a problem!

 

oh yeah , sorry dude, i'd been up for a long while (that my excuse and i'm sticking to it!)

i did actually know that as i'd checked mine 2 days prior

stevie

 

Mine was idling very poorly, ended up being an air leak just after the AF sensor. Maybe its that? Not that expensive then.....which is nice!!