I just happened to buy my very first car after owning a hell of a.muddin machine... Well i got my panties in a bunch and jumped on a car that when i test drove was only running 8 lbs of boost accordong to the gauge. And it freaking ripped..... Well in the time since i purchased it i was lucky enough to have to replace to lower ic pipe with a ets lp2 due to the garbage aluminum piece that was there missing the elbow to the turbo. Which made it hang low as hell....and scrape so that got replace very recent ly. And then i have had to do brand new tein s tech springs and rear struts since what i thought i had a slammed car... come to find out i had blowed out rear struts and d2 lowering springs that sagged so bad they had spring helpers in it to get it up and sadly it still ate tires alive which it dont now....not to mention a transfer case due to the previous owner not knowing how to launch so sadly i kinda have to say i bought a GOOOOOOOOD ONE. And now i am having boost leak problems... All couplers are tight i went over them all today trying to fix the leaks that recently started poppin up last week i had the boost controller adjusted and was holding a steady 21 lbs with about 2 lbs drop off at 5-7k rpms which is normal that i have heard and read about. Today i boosted and hit 12 lbs and that was it... So i said wtf.. thats when i went thru all my couplers and vaccum lines and everything. Was good vaccum wise and couplers tight.... And i took a drive only hit 14.5lbs... I dont understand what this thing is doing.. the evo 8 was my dream car and this one is quickly turning in to a great annoyance let me know what u all think ide really appreciate it... Sorry for the horrible spelling i typed all this on my phone

 

Could be the tb shaft seals going bad. Start by doing a boost leak test. If it has higher miles they tend to develop a leak a the throttle body where the shaft seals for the flapper goes through. If its that mil spec sells them like 20 bucks I think. I had this same 14 psi problem except mine was due to a cracked manifold. You check for any leaks pre turbo as this will cause significant amounts of boost loss. Any kind of leak before the turbo will cause this so make sure the manifold is tight on the head and to the turbo and neither gasket is blown, do a boost leak test as well and u should find the problem. Its not the factory boost pill like most will say since u have a boost controller and im assuming the boost pill was removed.

 

Ill look in to the throttle body seals..everything from turbo outlet to the throttle body got a good tightening.. today and the vaccum for the boost gauge is glued and zip tied i had q problem there before so it was the first place i happened to look. and as for bad gaskets. Ya know it would have a little putter from the exhaust leakig around it.. which i have no noises comming from there... What kills me is i was running 21 lbs perfectly fine ya know and just out of the blue its like a 8 lb loss which is pretty drastic to me i can tell a major loss of power and am dying to get it figured out. But i greatly appreciate ur advice. Another question.. how or what is the best way to inspect those seals i havent made the pressure tester yet so i cannot check it out by a pressure test yet

 

every boosted car should use T-bolt clamps instead of the weak factory worm clamps. i didn't think i had any boost leaks and then one day i replaced the clamp at the turbo outlet and i instantly overboosted by 4psi+. running the car hard with boost leaks causes the turbo to overspin and fail prematurely.

step 1: T bolt clamp how to
https://www.evolutionm.net/forums/ev...-how-list.html

step 2: replace the throttlebody shaft seals if you haven't already. you can buy them from any Evo vendors on here. i went with Aby @ Milspec because he got back to me the quickest. shipped them out the next day too.

after you're done those 2 steps, do a boost leak test
https://www.evolutionm.net/forums/ev...er-5-02-a.html

good luck

 

+1 for the t-bolt clamps, and a boost leak tester will become your best friend, cheap and simple to make I'm sure there is a quick write up using the search button

 

Mine was a sudden loss as well with the manifold being cracked and u might not necccesarily hear it as I couldn't hear it leaking and even after finding the crack and holding my hand there it really didn't geel like a substantial amount but that's what my problem was. As for the seals there's no way to test or check them without a boost leak test. They are located in behind the throttle rotor spring assembly and the opposite side behind the tps. U should hear them leak when doing a leak test and soapy water will produce bubbles there. If that's the problem complete disassembly of the throttle body and having new seals pressed in is the only solution. Theirs a how to in the how to section under the engine section stickies.

 

Found it...... Was a p.o.s $2.50 rubber grommet wearing out where my boost gauge was tee'd in got a small hole in it seriously made a big difference.... I replaced it and had 19-21 lbs all day no issues since just dewling with a bastard blow off valve now.... Grrr dont forget i purchased thr best evo 8 in the state of ohio and yes.... that is spoken with a insane amount of sarcasm i made a new post on that issue please check it out if interested.

 

you need to be patient with the evos