Really loud spool Options

[CELL_PROTOTYPE_X]

So I'm thinking I have a boost leak somewhere because my turbo sounds like a jet taking off when it spools up and it's not pulling evenly through the rpms. I notice a lot in 3rd getting on the freeway. The car will start to pull and then it will pull really hard (normally around 10psi) and will sometimes hesitate at high rpms. In first and second I can here what seems to be the turbo spooling but normally don't see or feel any boost until 3rd and through this gear and 4th it screams. I can get the car to boost in 2nd but I have to floor it...makes me think I have a leak somewhere. Are there any other causes for this issue? Plus I think I'm running a little lean My wideband normally is around 14 or so but have noticed it sometimes running around 15. Man it would be nice to find someone in Ohio with some st205 experience....

[nik]

check where your manifold connects to your turbo
if thats good

check all your i.c. piping

[Nartanian]

check where your manifold connects to your turbo
if thats good

check all your i.c. piping

+1 also check vacuum lines and hoses to make sure they are all connected or don't have air leak. Make sure your manifold has no cracks as well.

[mk7celica]

I have the same problem turbo is very loud and boost is unconsistant. I fixed all my ic pipeing so I have no leak so now I am going to replace 99 percent of the vacum lines because there over 10 years old so maybe ones cracked. But yea my turbo sounds like a jet also keep posted on what you find wrong cause It might help me out gl

[CELL_PROTOTYPE_X]

I'll keep you posted. I just bought new silicon connectors and am going to rework my IC piping. I've been having issues with my pipes separating under boost. I'll also be sure to check my manifold and all my bolts. I've had the downpipe off so maybe some bolts came loose and I'm getting a leak around there. Thanks for all the input guys.

[presure2]

your seeing 14-15:1 under full boost, after ~4k rpm?
if so, tahts really bad, and the reason your hesitating prolly. (if thats the case, your more than likely knocking)
i would look for leaks from the head to the manifold, or manifold to turbo ect.
thats more than likely where your leak is coming from, and why you can hear the turbo spool so well.

[CELL_PROTOTYPE_X]

I'll take the car for a spin tonight and see what the wideband says under boost and check for leaks. At idle the wideband normally reads around 14:1, upper 13's. The other day after boosting and slowing to a stop it was around 15 at idle, but only for a little bit. Thanks guys

[presure2]

it should be ~14.7-15:1 at idle, and cruising, once the car is warm.

[CELL_PROTOTYPE_X]

So I checked my exhaust manifold and turbo and couldn't find any noticeable leaks. I did though have a bolt that was maybe half a turn loose so maybe I was getting a small leak there. I took a couple pictures of some things I found.

I did find a cracked hose under the car, but not sure if this could be causing the issue. The issue could just be from the intercooler piping. I'm going to replace the pipe that I was having issues with with some bead rolled pipe and install new connectors.

This post has been edited by CELL_PROTOTYPE_X: Jun 3, 2009 - 10:10 AM

[pittfirefighter]

come to PA

[CELL_PROTOTYPE_X]

lol, trust me I would if my schedule permitted. It would be nice having someone close to help me diagnose some of these issues

Sorry for the large pics by the way...I didn't realize my camera settings were set that way

[CELL_PROTOTYPE_X]

Anybody know where that line goes that appears to be split? Seems like it runs up behind the manifold but can't see where it ends.

[pittfirefighter]

if youre talking about the one in the pic.. that looks like the two lines that go to the power steering pump... they run into a line on the intake manifold...

[CELL_PROTOTYPE_X]

Thanks! That's what I was looking for. The line seemed to be pretty old and cracked so I'm going to replace that...probably nothing to do with the issues I'm having but what the hell

This post has been edited by CELL_PROTOTYPE_X: May 22, 2009 - 7:56 AM

[CELL_PROTOTYPE_X]

Just posting an update...I replaced most of my intercooler piping with bead rolled pipe and I got high quality silicon connectors. Took the car for a spin on the freeway yesterday and pipes didn't separate under boost! I still need to do a leak test but I'm happy with the results so far and I don't think there are any leaks. I also found that my rear tranny mount bolt was about to fall out so I got that back in but the dash vibrates like crazy now, but the car handles 10X better! I also have been keeping an eye on my AFR and it seems to be around 14:7 at idle, but under boost it normally stays around that number and will sometimes jump to around 13 or so. I need to take it out a couple more times...my eyes are drawn right to my boost gauge so it could be performing ok

[pittfirefighter]

you want to be right around 13 under boost nice work

[lagos]

you want to be right around 13 under boost nice work

WHAT????
No you dont. 13afr is too lean for a turbo car. Its enough to blow your motor. You want to be at around 11afr under boost on a turbo car.

Cell Prototype, make sure the vac line to your fpr is hooked up.

This post has been edited by lagos: Jun 3, 2009 - 8:37 AM

[CELL_PROTOTYPE_X]

I'll check the line tonight along with my wideband Maybe I hooked my wideband up wrong and it's not reading properly. Can't have any motors blowing up!

This post has been edited by CELL_PROTOTYPE_X: Jun 3, 2009 - 10:04 AM

[presure2]

just to add,.. on a 3rd gen, it will generally be lean (13:1) before 4k rpm, which is totally normal, compared to a 2nd gen, which goes generally richens up much earlier
every stock ecu'd 3rd gen dyno ive seen follows that trend.
as long as it continues to richen up as boost and rpms increase down to a safe (~11.8:1 or richer)afr i would say your fine.

[CELL_PROTOTYPE_X]

Sorry to bring back this old topic but I finally got around to doing a boost leak test and found that my valve cover is leaking....most likely the cause of all my boost issues.

*EDIT: Actually I think I did the boost leak test wrong...I kept the oil cap on because I wasn't getting any pressure in my system when it wasn't. Hopefully I didn't F anything up. Car seemed to run like normal after the test so hopefully all is well Any clue why I wouldn't be getting pressure in the system without the oil cap on?

This post has been edited by CELL_PROTOTYPE_X: Nov 23, 2009 - 9:41 AM