redtop boost problem

[Vatche]

ok so car ran fine blah blah, it has an s15 turbo in it, with pretty much stock everything else cuz im broke. the problem is that about a year ago i was missing the bracket between the downpipe and tranny, so my turbo nuts would come loose all the time, during one of the times that they were lose i took my car to get it smogged and i dont know if he tampered with something or not but after i fixed the turbo nuts and bracket problem, my car would bog at boost so i raised the idle from 750 to about 850-900 and the problem was fixed. but i didnt feel like i had much power. i felt a power loss and just recently after maybe 6 months or so of driving it im starting to troubleshoot the problem. and i checked the timing, with the gun set to 15 advance it was on the 3rd line from the right instead of the second one i guess where it is supposed to be, and thats all i know. my car is boosting at 3.5-4psi is what the problem is. but i dont know why. and im wondering if u guys might have any ideas of things to check , maybe if something is going bad ? please help me out. im lost.

[180InProgress]

Did you check all vacuum lines? I had a problem like this recently and it turned out I boosted to high and blew the vacuum line right out of my charge pipe.

[Vatche]

well i dont have a boost controller or boost gauge, but before my boost gauge was stolen...over a year ago it was boosting stock, and ive never fiddled with the boost...it just suddenly dropped, i used a boost gauge the other day just to check my boost and it was only boosting 3.5-4 psi,

i just raced an m3 and he pulled pretty bad in 3rd gear on me. i used to keep up with them just fine. so i dont know :( im sad

[Vatche]

oh and the vacuum was at 15 or a lil more...so i dont think there was a leak

and ive checked all the lines they look fine.

[180InProgress]

did you try running the car and let it sit at idle, and spray vacuum hose inlets and the turbo gaskets with carb/choke cleaner? From what I hear, if there is a leak your idle will rise when you do this

[motegineon]

hmm, still sounds like possible vaccum leak, my vaccuum is at around 20-21....also gaskets after manifold? turbo gasket i known to go bad..

[Vatche]

ill check for a vacuum leak today, if u guys have any other ideas maybe lemme know

also the turbo gasket should be fine ive replaced that many times and it should be fairly new. but i know it to go bad...if i didnt put in the bracket between downpipe and tranny i was going through studs and nuts once every 3 months or so

[Vatche]

does anyone know what it might be?