93 wrx intermitent stutter when warm and rev drop at idle. MAF?
 

hi guys :thumb:

thought would put this up to see if anyone has any bright ideas

had a issue whith this car since i got it few months ago. it seems to run fine from cold but generally at warm temp normally after 15min driving i keep getting what feels like a fuel cut off

it does it at a steady speed on at a flat road about 3k as well as under boost.

since it is colder weather seems to be getting worse, but may be a co-incidence

if it has this feeling of loss of power it drives normally for a bit. when pulling upto lights/roundabouts as soon as the clutch depressed and the revs drop it idle drops off to stall

i have read the codes and got maf and iacv. took iacv off cleaned it with cleaner and replaced. iacv works fine free as a bird and works fine from cold and idle

i bought a second hand maf and replaced, cleaned that before fitting but looks in good shape. reset codes and drove, problem is still there.

codes brought up maf and tps when checked again, so inspected tps loks good checked resistance while opening inlet and smooth readings.

cleaned maf again, checked spark plugs and ignition leads, fine. still have the issue.

fitted a gauge to fuel pressure line and fuel is just over 2bar to 2.5 when reved and holds pressure anter engine off so think pump is ok but i have to get gauge into the car so can see if it drops with the stutter whilst driving

read about disconecting maf sensor when engine warm and runing, it tries to stall but recovers repeatedly without stall and keeps going. i heard this indicated maf was fubar

however i have also read this is bs and proves nothing

does this mean its the maf? i am going to buy another, but brand new this time.

if anyone has seen similar expierence would appreciate any insight to see if im going the right way.

thanks for reading :lol:

I had similar stutter under boost. Got uprated ngk's and it's fixed the issue.

hi there, thanks for your reply, when i checked the sparks they were ngk too, looked good gave them a clean anyway and the gaps looked good. but deffo a thought if all else fails. thanks!!!

havin similar issues in my 97 wrx same cutting out at lights and stutter between 2 to 3000 rpms only when hot have to drive it 10 miles before it happens after checking all hoses replacing maf and temp sensor i'm told its probably o2 sensor as had codes 23 and 24 cleaned the iacv as well no code coming up now tho i would remove the o2 and test it ( ace little vid on you tube if unsure how to ) good luck as there is nothing worse than scratching your head like i have been doing for the last week :thumb:

rob

+1 on the idle control valve..give it a good clean out with brake cleaner and see how she fairs!