hello i hope this explanation helps ..........
i own a 95 wrx wagon with mods as discribed below
front mount intercooler
headers and up pipe
bozzspeed ecu with 17 psi (dyno'd at 319 atfw a little lean at top end) 250 at the wheels.
k+n cone filtter
3in turbo back decated exhaust
its some beast lol
my problem is i have recently developed a misfire through the intake and a bogging down sound....almost like a long gasp of air before it will rev then miss then POP through the intake. driving is almost impossible as i need to build up the revs to about 3-4 k before it will move, coughing and popping. (i dont know if this is causing more damage driving it) the boost will build up, but as soon as it has then the above starts. its not at boost but low rev range onwards.worse under boost
also i have noticed that when the maf is unplugged the car will start and rev normally (is this normal??) ive not tried to drive like this as i dont want to cause more damage to it.
things have tried are
removed turbo to my spare one (td04 but works fine) thinking it was that
checked plugs and coilpacks (plugs are VERY SOOTY)
checked for vac leaks (none seen)
looked for loose plugs on loom
ecu reset (z4 ecu remapped by bozzspeed japan)
check fuel line pressure
removed maf sensor and replaced with new one (well 2nd hand but working)
compression test (figures at 160psi an 3 cyls and 155 on the other)
i have run out of ideas and comming to the end of my wick with it....... if i had a bomb it would be all over the street where i live in bits lol. this is how im getting with it.
can anybody help on this please or point me in the right direction of what to look for......?
i know you guys an gals are quite clued up on things, lookin through this site...please help or i fear its gonna be one less wrx on the roads (hopfuly not)