pwoens Posted February 2, 2017 Share Posted February 2, 2017 Hello everyone, Kids car is a 2003 subaru forester 2.5 x 160k auto. Replaced head gaskets last year prior to kid getting her license - made her help . Once she started driving we quickly found out the gas tank had a faulty vent valve and gave us the notorious issue of slow fill at the pump. We identified the vent valve as the culprit and replaced it. (that job was horrible BTW!!). It idled and ran fine prior to replacing the vent valve in the tank but after the vent valve job was complete we have had a difficult time getting it to start without giving it gas and it idles low most of the time, especially when cold. We did unplug the battery during the vent valve job and found out this can cause a loss of memory on appropriate idle level in some cases??? Here is what I have done to date trying to resolve the intermittent bad idle and not starting without giving it gas: replaced fuel pump reset/relearn the idle by unplugging battery, draining battery, plugging battery back in, turning ignition to on, waiting 10 seconds, and ten starting the car without touching the gas. Important note: The care would NEVER run after plugging the battery back in UNLESS you gave it gas. I even tried turning it over countless times hoping it would learn on its own. This process never would work for me. Cleaned the throttle body thoroughly inspected all hoses going to fuel pump. It runs fine when you are driving it, just idles low and hard to start. unable to find a MAF on this sub anywhere Anyone have this issue and find a resolution? Appreciate any insight anyone may have. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted February 2, 2017 Share Posted February 2, 2017 any check engine lights? vacuum leaks often cause this - too much air and giving it gas will overcome a slight leak. check fuel pressure after the filter? Quote Link to comment Share on other sites More sharing options...
pwoens Posted February 2, 2017 Author Share Posted February 2, 2017 any check engine lights? vacuum leaks often cause this - too much air and giving it gas will overcome a slight leak. check fuel pressure after the filter? No check engine lights and no codes being thrown. The AT Temp Light will flash when idle is really low. I have never understood a good way to check for vacuum leaks - any quick insight on proper route to check this? Same with checking fuel pressure - not sure how to do that?? Thanks buddy!! Quote Link to comment Share on other sites More sharing options...
CNY_Dave Posted February 2, 2017 Share Posted February 2, 2017 Sounds a bit like my '05 2.5x forester- every 80k miles or so the EGR valve sticks. I take it off and clean it. Quote Link to comment Share on other sites More sharing options...
ferret Posted February 2, 2017 Share Posted February 2, 2017 Sounds a bit like my '05 2.5x forester- every 80k miles or so the EGR valve sticks. I take it off and clean it. I thought of that when I first saw this thread, but IIRC, the 03 does not have an EGR. None I ever saw did. The 04 Forester brought it back... the electronic Mitsubishi one. Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted February 2, 2017 Share Posted February 2, 2017 (edited) does it start or idle better after it's warm? kinda seems like IACV problem or possibly engine temp sensor? you might read here;http://www.scoobymods.com/showthread.php/forester-2004-intermittent-poor-idle-p118676.html#post118676 Edited February 2, 2017 by 1 Lucky Texan Quote Link to comment Share on other sites More sharing options...
pwoens Posted February 3, 2017 Author Share Posted February 3, 2017 does it start or idle better after it's warm? kinda seems like IACV problem or possibly engine temp sensor? you might read here;http://www.scoobymods.com/showthread.php/forester-2004-intermittent-poor-idle-p118676.html#post118676 It does seem to start and idle better after its warmed up. I read that scoobymods thread and was leaning towards the IACV and that thread has me leaning more towards it now. Just wish they were not so darn expensive lol Quote Link to comment Share on other sites More sharing options...
Olnick Posted February 3, 2017 Share Posted February 3, 2017 You probably don't need a big bucks new one. Just pull yours and give it a thorough cleaning. Quote Link to comment Share on other sites More sharing options...
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