legacy b4 HELP NEEDED,,bad misfire/wont idle/low idle,with video

Had plugs out b4soon....im not an expert on plug condition but they were very black and one of the plugs was loose enuf to screw out by hand !!!! I refitted them all tightly ay checked the coils they all seemed oj..no cracks or splits under the rubber booths ..
 
Ok. Next thing you need to do is completely rule out the maf. Try to find someone with a b4 thats running fine and swap the maf. Word of caution,may 2001 onwards have different mafs.
 
You could get a loan of a fuel pressure test kit, subarus are real easy to do it on, the fact it's ticking over so low but yet you don't hear any difference when you unplug a coil at a time could mean its fuel related. Could be your fuel pressure reg is gone or blocked fuel filter,

Have you done anything at all at the car before the problem started??
 
All i did ken was clean the vac lines ...they were all full if crap.the car ran great for a day ir two afterwatds then this happened ...
 
cleaned idle control valve already ken,,,,it was manky dirty..didnt make any diff when i put it back in,,i tested the tps sensor tday with a multimeter and got a reading of 0.5v at idle and 4.7-5.0v on wide open throttle ,,which i take it means its ok....ive just bought new plugs online for her (NGK PRF6B) as the old ones were badly fouled up ad one was loose enough to be removed by hand !!!!! and i removed the intercooler earlier to inspect the throttle body.that seems ok too
athough i was looking on u tube and cam across a video of a failed tps sensor and the noise it makes ,,,and mine makes the same..this dosent make sense as it checked out ok on the multimeter,,,..anyways heres the videos..mine is the second one,,see what ya think

http://www.youtube.com/watch?v=Umv9fL9hbOw

http://www.youtube.com/watch?v=cln2opxsS90
 
The M A P sensor could be your problem, it is in the inlet manifold or one of the air inlet hoses or pipes. Iam not sure where it is on a legacy but it has given me grief over the years on all different models of cars, same symptoms. the veins get blocked and the engine compensates by over fueling or under fueling which will cause a dirty idle or misfire when revved, sometimes. Might be worth a try, it can be cleaned easily enough with petrol and paint brush, could be a dead plug aswell. You said you fitted a new boost gauge, make sure its air tight at the connection.
 
Well im hoping i hav solved this ....my plugs were very black when i took them out...also the gap on them was huge..im talking far too wide here..ive ordered a new set of prf6b ngk plugs an along eith the repair ive done to my leaking purge control solenoid..i think i may have sorted it...im praying i have..
 
It was runing perfect on them plugs before you said so cant see them being the problem. But it wont hurt to change them :thumbsup:
 
Did a bit of playing around with the maf sensor today after I twitted all the spark plugs an coils .. Plugged maf out while she was idling badly an misfiring , when I did plug it out the engine spluttered a bit an next thing the revs shot up to 900rpm an held steady . No misfires or spluttering !!! As soon as I plugged maf back in the revs dropped an she began to run rough again ... Looking like I need a new maf so????
 
[quote author=B4 soon link=topic=36483.msg417907#msg417907 date=1356698358]
Ok. Next thing you need to do is completely rule out the maf. Try to find someone with a b4 thats running fine and swap the maf. Word of caution,may 2001 onwards have different mafs.
[/quote]

Just re-quoting myself from few days back......
 
Cheers b4 .... It was actually when I read back over this thread and re read your post that I decided to go playing with maf ;)
 
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