Cant remember if you said the PCV was checked or cleaned/ replaced (few $)? Old school test (not sure its accurate today w/ modern emission system) was to shake the valve, if it rattled- was OK- I did a so so cleaning of mine. Maybe the hose is working ok, a spray down of WD 40 at its juncture(s) could tell if leaking. (idle change or surge)

EDIT: You did change PCV, if the hose isn't drawing in air...

Edited December 19, 201114 yr by propane

PCV was replaced - altho the old one did still rattle and fairly smoothly, too, despite all the gunk on the outer edges.

 

i did find that using a heat gun breifly (and carefully) on the hose did soften it up enough to make reinstalling a little easier, but dang - when it was cold, it was hard as a rock.

following is the link to idle air screw (early legacy) legacy 777 post looks like it could carbon up- an easy clean or back out a fraction of turn

 

 

http://www.ultimatesubaru.org/forum/showthread.php?t=42733

Edited December 19, 201114 yr by propane
EDIT;

idle level (when it isnt surging) is perfect - according to FSM, it should be about 700 RPM (+/- a little) for the automatic - i believe the manual version is just a little higher - so I will not be messing with any of the "adjustment" screws.

 

cold start to full operating temp (no driving) it is dead on - sitting at a traffic light, in gear, it is dead on - sitting in my driveway after driving, in gear - it is also dead on - but the second i put it in "park" after having driven somewhere - that is when the surging starts.

 

previously - i could not get it to settle into the 700 RPM range and stay there no matter how hard i tried, now I can (or at least i did last night when i got home - havent driven it enough yet to know if it will do this consistently or not)

thats good idea not to change factory settings- those w/ paint - maybe the ECU has to relearn , and the idle RPM sounds about right, as per under hood sticker, autos are the higher one for the benefit of the torque converter, good luck

just a little update on this one - the ECU is slowly "relearning" the idle curve and the warm idle in park is gradually getting smoother - still wants to wander just a little when initially stopping & putting in park, but it smooths out much faster now

 

I may force the issue by doing an ECU reset - but for the moment, it is much better than it was - would really like to get some of the bigger hoses replaced (primarily PCV system hoses) but cant seem to find those available for purchase anywhere - can someone point me in the right direction???

 

was told heater hose was not a suitable replacement - am open to other suggestions - 21 yr old hoses are getting pretty hard and not sealing very well...

well - phooey - still having surging issues once warmed up more than a month later....

 

again I ask...

 

would really like to get some of the bigger hoses replaced (primarily PCV system hoses) but cant seem to find those available for purchase anywhere - can someone point me in the right direction???

 

was told heater hose was not a suitable replacement - am open to other suggestions - 21 yr old hoses are getting pretty hard and not sealing very well...

 

for those that dont want to take the time to read the whole thread...

1990 Legacy LS, AWD, Automatic - now has 222K on the clock

 

have already replaced:

IAC valve from a lower mileage car that was a known runner - cleaned out before installing

Coolant temp sensor

all the smaller vacuum lines

Radiator replaced recently and filled with fresh fluids, system burped

PCV valve (larger hoses need replacing - see above)

MAF sensor (from the same car as the IAC valve)

oh yeah - O2 sensor was replaced last year...

 

anyone have any other thoughts, suggestions, comments????????