3rd Generation Specific (1993-2002) 1993-2002 Discussion including performance modifications and Technical Support Sections.
Sponsored by:

Yet another boost issue.

Thread Tools
 
Search this Thread
 
Old Sep 26, 2006 | 12:06 PM
  #1  
optimus prime's Avatar
Thread Starter
Full Member
Tenured Member 05 Years
 
Joined: Jul 2006
Posts: 59
Likes: 0
From: Los Angeles
Yet another boost issue.

Well, here's the deal. I recently acquired this car less than two months ago, so as of now, I'm very much learning the way the rotary works. My current problem revolves around secondary boosting, I'll try to be as descriptive as possible in explaining it ( I have searched. )

Boost Pattern: 9-5-5

Yesterday I was trying to diagnose my boost issue: I removed my air box, pressure chamber (held pressure) and removed various hoses and couplings to verify they weren't cracked or leaking. I checked the pills in the wastegate lines to make sure they were there and to check if the lines were loose. I switched the two plugs directly under the UIM to see if that was the problem, no dice. I also disconnected my main Cat to see if it could be clogged.

However, I did notice a sliced vaccuum hose going from some sort of actuator directly above the Y-pipe (don't know what it's called?) to the UIM. I repaired this hose and secured it back on to the actuator.

Here's how the problem sounds: It sounds almost as though there is some sort of Venting sound coming on TWO times during my power band. From 1-2.5k rpms, i hear this vent, then at full boost, it dissapears. I continue to 4.5k prms where the switch is supposed to occur, and again this VENTING of air comes on all the way to redline. It almost sounds like a wastegate of somesort? It makes a PSSHHH sound all the way to redline.

Any ideas on where this venting could be coming from? and if it's possible that it's venting my secondary turbo boost? TIA
Reply
Old Sep 26, 2006 | 01:06 PM
  #2  
BuffDaddy915's Avatar
Tha ladies man
Tenured Member 15 Years
 
Joined: Oct 2003
Posts: 1,170
Likes: 0
From: Chicago
I would start by checking your Turbo Precontrol Vacumm line. When your looking at your turbos from the front, there is these 2 pot lookin things with vacumm lines coming from 1 side of them. Check the one on the bottom.

I would also take a look Turbo and Charge Control Vacumm lines.

Turbo Control is under the UIM. There is a conncector in the middle area on the left (passenger side). Check the vacumm hoses connecting to that.

Charge Control line connects to the outside (passenger side) of the LIM. Its the bottom hose. Then follow that back to the turbos and through under the UIM.

Start with that, then give us an update.
Reply
Old Sep 26, 2006 | 01:47 PM
  #3  
optimus prime's Avatar
Thread Starter
Full Member
Tenured Member 05 Years
 
Joined: Jul 2006
Posts: 59
Likes: 0
From: Los Angeles
Ok i'll check all that stuff out and let you guys know what happens.
Reply
Old Sep 27, 2006 | 12:40 PM
  #4  
optimus prime's Avatar
Thread Starter
Full Member
Tenured Member 05 Years
 
Joined: Jul 2006
Posts: 59
Likes: 0
From: Los Angeles
Ok after countless hours of searching, it seems as though the venting i'm hearing after 4500 rpms is most likely the charge relief valve not shutting. I haven't gotten a chance to check the lines that were mentioned yet, as i will be giving it a once-over on saturday when i have the time to; however, assuming it is the charge relief valve being stuck open, what sorts of things usually fail that cause that problem?
Reply
Old Sep 27, 2006 | 01:42 PM
  #5  
Kas's Avatar
Kas
Full Member
Tenured Member 15 Years
 
Joined: Oct 2002
Posts: 129
Likes: 0
From: virgin islands
I had a similar problem last week it turned out being 2 loose nuts that tightenthe throttle body to the upper intake plenum,I had a huge boost leak for a few moths and thats what it was.
Reply
Old Sep 27, 2006 | 04:20 PM
  #6  
BuffDaddy915's Avatar
Tha ladies man
Tenured Member 15 Years
 
Joined: Oct 2003
Posts: 1,170
Likes: 0
From: Chicago
Well if the charge relief vavle is staying open then it just failed period.
Reply
Old Oct 22, 2006 | 11:04 PM
  #7  
optimus prime's Avatar
Thread Starter
Full Member
Tenured Member 05 Years
 
Joined: Jul 2006
Posts: 59
Likes: 0
From: Los Angeles
I know this may sound dumb, but does the CCA have anything to do with secondary boost issues? Reason being is that i was trouble shooting some more today and i found that my CCA doesn't move (did the KO/KO test.) If i read correctly, however, the CCA only affects primary boost? The funny thing is my primary boost is fine at 9 psi, but secondary drops to 4ish.....any info on this?
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
rgordon1979
3rd Generation Specific (1993-2002)
40
Mar 15, 2022 12:04 PM
Jeff20B
1st Generation Specific (1979-1985)
73
Sep 16, 2018 07:16 PM
Bauer778
3rd Generation Specific (1993-2002)
10
Nov 4, 2015 04:42 PM
High_Carb_Diet
Power FC Forum
1
Sep 5, 2015 09:07 AM




All times are GMT -5. The time now is 07:29 AM.