Boost leak???

ok i was driving today and when i tried to accelerate hard i could hear my boost kick in but my car was hardly accelerating...i could hear my turbo spool as loud or even louder than it normally does when this happened....also i know its not acccurate but on the stock boost gauge...when this problem happens the needle will go all the way to the top (showing full boost) it will sound like the cars turbo is working hard but my car accelerates MUCH slower than normal...and even jerky at times ..its like it gets a little power and a little gets taken away so the car doenst run very smooth when this problem occurs. This problem is only noticable around 3k rpm...Im not sure if its my imagination but when it happens i think i can hear the turbo trying to work a few RPM earlier than normal and sounds slightly different...my car is a stock 1997 eclipse Gs-t with an injen intake only...any input would be appreciated. If i go to a normal mechanic and ask them to check for "boost leak" will they know what the hell im talking about??

Leaking Blow off valve :dunno:

Leaking Blow off valve :dunno:

so i know you cant be sure of anything off the internet....but from what i described, you think it could be a leaking blow out valve more than anyting else?? and if it is not the BOV than what else could cause a problem like this....i will probably be upgrading to a 1g BOV soon as i can get my hands on one.

check your lines and hoses. every time i have that sht happen to me, somethings always come undone.

I have the same problem currently. I think it has something to do with the cold weather(I live in PA) AND how your plugs are gapped. Make sure that they're gapped between .28-.32 and see if that helps. Like i said, i've posted on this very same subject before, and i have the exact same probably currently, but mainly only when it's cold, and it's gotten better since i regapped my plugs from stock (.45) to our car's specs. Try that one out and see what happens.

Everything in the original post tells me a boost leak has opened up somewhere. And stop crying "stock 2G BOV," his car is stock with an intake, if it was the BOV he would have noticed it before I'm sure. There is a difference between a BOV that opens slightly and a cracked hose or something else major that will provide the symptoms mentioned in the original post.

Bad plugs/gap will almost always show up as a misfire.

I wouldn't bother taking it to a mechanic, they wont know what you mean. I would read the vfaq on how to build the tester, and test that shit yourself. Most leaks can be found in a matter of minutes. If you really cant find a leak, and dont know these motors that well, take the tester to the mechanic and show him what it is, and tell him what you are trying to accomplish. He should be able to take it from there. But try yourself first, why the hell not. Probably an easy fix like a bad clamp or a blown off hose.

Also, there is a reason the stock boost guage pegs high when you have boost leaks, even though boost either hasnt changed, or has gone down. The ECU uses airflow measured by the MAS to make a guess at what the boost is. If you are blowing an extra 5 lbs/min out a cracked IC hose, the ECU doesn't know that its not making it to the motor. This is also why it runs rich when this happens, the ECU is adding enough fuel to cover all of the air going through the MAS, but less air than that makes it into the motor.

wow gsx your freakin smart...i thank everyone for the input really...I think you might be on the right track GSXracer because i think my car is running a bit rich and its not because i didnt recirculate.I doubt its the cold los angeles weather even though its been colder lately..I was going to get a 1G bov soon so if thats the problem it will go soon...if its hoses or clams i have to figure out how to make the tester then look and see...i guess my only question from here would be this...if this leak is coming from a hose or somthing like that wouldnt it be noticeable 100% of the time...because it will happen somtimes and then go back to near normal boost some other times

Its not uncommon to have a hose that is split and there is no way to tell until some pressure is reached, or a clamp that is stripped, but feels like its still tightens up enough, etc. Thats why the only reliable way to track boost leaks down is to build a leak tester and pressurize the system. Listen for hissing sounds, use soapy water, etc. If there is a leak you should be able to find it. Some can be tricky though. For example, a leak at the bottom of the intake manifold. Just impossible to see down there or spray the soapy water on it. But those type of leaks are somewhat rare, you can usually find them all in 10 minutes or less. HAve fun :)

I can't believe no one asked about his clutch slipping. Ive felt that in 2 diff cars.

But Def. listen to GSXracer. you HAVE to have tight hose clamps on al your IC piping. :smile:

On my car, a slipping clutch will LOWER my boost, because load is reduced. On a more normal turbo size, this may not be the case, since less load is required to keep it spooled up. Its important to remember that turbos are load dependant. Jsut wanted to point that out, even though my case may not be the norm. :)

Here's the air tank you need to get to test the intake. Also be sure to get a bike tire tube with the valve attached not a car tire valve. Thought this might help.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=4534916987&category=43986