I bought this car a month ago and it's always seemed sluggish and had a low idle when I got the car (500rpm) so I figured from day 1 that I had a boost leak or vac line tear. I put a k&n filter on and tbe. Took off the intercooler and replaced the rear y pipe gaskets, bov gasket, put on low mileage sti diverte valve.... Also have Cobb ap stage 2 map on the car....
I went into the boost live data on my ap and at idle I have -8 vac pressure??? Idle is still at 500 rpm, it should be near 750 and I'm guessing its because be vac leak, so I've spent 3 hours today with my boost leak tester and squirt bottle spraying every hose, every connection, every gasket, capping off lines, adding clamps to lines, trying everything I ****ing know to do and can't find anything
When I put air into the intake it fills up and I can't hear air leaking or see bubbles anywhere and then when I try to put my tire pressure gauge on the valve stem on my tester there is no pressure there. Won't even pick up 1psi, but when I push the valve stem with my finger the air rushes out so I know there is still some air pressure in there. Also the black purge valve that comes off the intake and the intake manifold and then goes down under the intake manifold.... It will start to make a squealing noise after about 20 seconds with the air hose connected to the cap. Then as soon as I pull the hose off the noise stops.
Also when I'm driving and I go into boost i can hold 13 psi consistently.. It doesn't taper off or jump its steady boost but I cannot figure out wtf is going on with vac pressure, also guessing with my low idle and bad Vac pressure that its throwing off my timing and being the reason it runs like ****... (Very laggy down low)
Also replaced crank angle sensor today as well as another thing to write off my list, could it be bad iacv gasket???