98 SSEi, No boost. - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat

Forced Induction All questions and problems regarding Superchargers, Turbos, NOS, ZEX, intercoolers, water injection, etc.

Thread Tools Search this Thread
Old 02-08-2006, 11:06 PM   #1
Senior Member
Posts like a Northstar
Thread Starter
Join Date: Mar 2003
Location: Brewerton NY
Posts: 551
Thanks: 0
Thanked 0 Times in 0 Posts
karfreek is on a distinguished road
Default 98 SSEi, No boost.

My dads friend has a 98 SSEi (Silver) that suddenly is not buildling boost. The needle goes from -10 to 0, but not over and has diminished performance.

So far I have told him to check that the belt is there and what I Beleive is the BCA, the round thing that has the arm on it in the front of the */C. What else should we look at?

Also, what is the BCS vs the BCA?

karfreek is offline   Reply With Quote
Old 02-08-2006, 11:38 PM   #2
Senior Member
Certified Car Nut
Join Date: Mar 2003
Posts: 12,432
Thanks: 0
Thanked 0 Times in 0 Posts
J Wikoff is on a distinguished road

You found the BCA. The arm moves in and out to rotate the shaft the bypass valve is on to open and close it. The BCS is the little box connected to the other end of the vac line that comes out the bottom of the BCA. It dumps boost when the PCM sees fit.

Can you pull the two halves of the BCA apart? What happens if you pull the vacuum line off the bottom of the BCA and run it? And check over vacuum lines running to and from the BCS, BCA, and MAP sensor for cracks. Is it possible the SC outlet gasket is blown?
J Wikoff is offline   Reply With Quote
Old 02-09-2006, 12:25 AM   #3
Junior Member
Posts like a Ricer Type-R
Join Date: Aug 2002
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
willwren is on a distinguished road

John'* got you covered on this one.

If you pull that vac line off the bottom of the actuator, the PCM can't command the BCA to dump boost via the BCS.

In a nutshell, the boost control SOLONOID controls the ACTUATOR. Lots of factors are involved in what and when and why the PCM tells the solonoid to do something with the actuator. The actuator is DUMB, and only does what it'* told by the solonoid. So if your solonoid is bad, you can prevent it from telling the actuator to do the wrong thing by disconnecting that line (don't leave it that way as a fix, as it could be a bad thing later).

Disconnect that line, if the boost returns to normal, either fix a vacuum leak or replace the solonoid.

If the line being disconnect makes no difference, your problem is most likely a vacuum leak or a faulty actuator.

Or as John mentioned, a leaky SC outlet gasket.
willwren is offline   Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
Low boost, no boost problem immusicman Forced Induction 12 09-27-2009 01:05 AM
Boost Control Solenoid Maintenance and Boost Control Actuator Test for low Boost* Toddster Trouble shooting + Test Procedures 0 03-21-2009 07:24 PM
More boost via boost controller... DanCulkin Performance, Brainstorming & Tuning 14 07-02-2007 12:02 PM
low stock Boost vs high stock boost hvactech Performance, Brainstorming & Tuning 12 05-10-2005 11:14 PM
95 SSEI - all series 1? what boost stock? DanCulkin Performance, Brainstorming & Tuning 20 11-06-2002 10:18 PM

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

All times are GMT -4. The time now is 09:07 PM.

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.