Well Im about clueless as to why/where I may have a vaccum leak, so I would really appreciate it if you guys could help me out. I had another thread about this, but its been a long time since then, and I have tried many things, so I decided to start fresh. Ok, it all started when I took my UIM off to paint it all up, and polish some other parts. Ive had my, and a few other FCs manifolds off many times. Ive also taken out and reinstalled engines before, and consider myself fairly knowledgable on N/A engines and intake systems. Anywho.. so when I went to put everything back together, I started it up, and when it tried to idle it just dies. Also, (this is weird..) it makes a high pitched screeching sound (sort of like air coming out of a balloon..). So I'm like.."ok, I just have a vaccum leak somewhere.." When I spray carb cleaner under the UIM, it seemed to smooth out a bit. So I figure, the only thing under there is the EGR, and the primary injectors (which I didnt touch BTW..) So I thought this to be puzzling. But anyway, I ordered all the intake gaskets, including the LIM-housing gasket, EGR,BAC, new injector O-rings and grommets, about every intake thing I could think of. Well I just got done installing all of the new stuff, started it up, and ....it still has that high pitched squealing, and wont hold an idle, unless I hold the gas at ~4k rpm or above. WTF! I have no idea what is wrong. I've even tried another set of manifolds I have, and still the same thing. Ive had this off and on probably 1/2 a dozen times trying to figure out what the problem is, and for the life of me I cant.. Any ideas would be greatly appreciated. Im very pissed....
Thanks..

 

Is your noise coming from this thing?

 

Hmm...not sure but I do remember even when my car was running properly I seemed to have a small leak coming from there.. I guess I could check that out tomorrow, thanks for reminding me. Just out of curiosity, why did you point that out, did you have a similar problem?

 

Black13B did. I found him a used one for $10. It's a check valve having to do with the idle or something.

 

Was he able to hold an idle at all, or was it just a poor idle? My car wont idle unless I hold the gas at ~4k or above. I was thinking of testing the AFM tomorrow also. But this only happening after I had the manifolds off makes me think its a leak of some sort.. But I suppose something could have happened to that white cylinder on the back of the TB while it was off..

 

Just a crappy idle, but his TPS was pretty much smoked, too.

Coincidences happen all the time with these cars. Grab a manual and start testing the usual goodies.

 

ahh yes that valve.. to be honest, i have yet to install that! its sitting in my console in the car.. which reminds me Amur_ picked it up for and I still haven't tossed him the 10 bucks! (next time we meet up )

anyways.. i had some big problems when i first got the car.. nothing major, but enough to cause some concern.

first up, was that it wouldnt hold an idle. second up, was it was a big dog throughout the powerband and misfired like there was no tomorrow.

i was stumped, and had little knowledge of the car (at least little as compared to the knowledge ive gained throught experiences with it.)

new plugs = no change
new battery = no change
new fuel that hadnt been sitting for lengthy time + FI cleaner = no change

as a cheap test, i added a 4 gauge ground from the battery right to the lead coil mount. it was going to be just a test, as i had read if the ground was bad, the spark would be bad.

driving + ease of idle was instantly improved, took it for a spin, car was amazing.

still always wanted to die at idle (and usually did) and if it did manage to pull it off, it was 500 - 1000 rpm up and down, almost stalling in between.

lack of exhaust backpressure from a leak causing idle problem (unlikely but needed repair) = no change
boost sensor test and replacement = no change
tps adjustment = barely any change
tps check and replacement = there WAS a change, but then after a few adjustments it still begun to idle like crap again
AFM check = good, no change
atmospheric pressure sensor = good, no change
battery check and replace = no change

that was all i managed to get around to, as i was shopping for a new alternator at the same time.

i had mine rebuilt, magically my idle problems disappeared entirely.

which brings me to the conclusion that alot of problems have to do with voltage.

on a 17 year old car, with a reputation for cold solder joints and other bad electrical connnections, logically alot of problems would have to do with voltage and current.

so my suggestion would be to test the battery and alternator, and inspect the battery connections, etc etc. doesnt take very much time at all, and probably would save you headaches with other things that use power .

some people say electrical work is the worst, but i find its pretty simple, and relatively inexpensive to repair..

sorry i cant be of anymore help, but thats all it took to solve my idle! new alternator!

the alternator wasnt bad, it still charged everything, but i dont know.. i guess since it solved the idle, then it was going bad..

 

Well thanks for the info, but I think we have different problems. This is definately a vaccum leak of some sort.. My Batterty is new ( < 3 month old Die Hard Gold) Alt is less than a year old, and I have recently addes all new grounds (way before this stupid intake problem) So I guess I just have some searching of my own to do in the next few days.. *sigh*.......... Thanks alot though

 

Go get your alternator bench tested. Most places will do it for free...

 

The sound you mentioned reminds me of a bad diaphragm. The ACV is a good place to check.

 

like i say i was only shopping for a new alternator because i knew the stock ones only put out ~60 amps.. i was planning on adding some electronics that demand more power, so getting an alternator was the next step for me.

the car showed no signs of a bad alternator (although i didnt have it tested)

the only signs it gave me were the regular signals you get when you have an alternator that only puts out ~60 amps.. (turn on alot of electrical loads and down goes the voltage..)

 

I have my own alternator testor, the alt is fine. It being a bad diaphragm sounds more reasonable, would a bad ACV or EGR cause the car to leak vacuum severely like mine seems to be doing?

 

i recently had my uim off and once i put everything back together it also made that high pitched noise, it was so loud if i were to close to the engine it hurt my ears. any way, i took everything back apart and realized i hadnt cleaned the old gasket off completely so the new one never seated properly. once i scraped the old gasket off, and put everything back to gether it was fine. no more screach.

 

I have a buzzing sound emitting from the ACV. And i still have the misfire issue, the last "solution" was a fluke... i had the a/c on

So now i'm down to testing the ACV (waiting for the vacuum pump), replacing all vacuum lines and grommets for injectors...

it gets worse and worse the hotter the temperature is outside and the hotter the motor is. So I'm thinking ACV as it is DIRECTLY ABOVE the turbo... and it's noisy... and it's stupid.

 

Yea, Ill have to test my ACV and EGR, or just swap them out. Ill post back as soon as I make any progress. Anyone have any more ideas?

 

any luck??