I'm confused.... (Low boost)
Thread Starter
Senior Member
True Car Nut
Joined: Jan 2003
Posts: 7,099
Likes: 0
From: Bonney Lake/Ellensburg, Washington- WCBF '04, '05, '06, '07 Survivor-

Originally Posted by wjcollier07
well u did say it happened after u replaced the supercharger..maybe a bad supercharger
Senior Member
Posts like a Corvette
Joined: Nov 2005
Posts: 1,201
Likes: 1
From: Hamilton, Ontario , Canada

You said it was fine , then you changed the SC and it lost oomph, so sounds like you need to look for vac leak at SC or a line , is the boost actuator working properly.Check , check , check for vac leaks
Need to see if the BCA and BCS are working properly. Superchargers don't produce low boost unless they lose their coating, and Gen2 superchargers don't have coating. It'* either belt slip or a vacuum leak or a bad component (BCA or BCS).
John, do the Bypass trick and see if you get full boost back. Scan and check for KR when you make that run.
John, do the Bypass trick and see if you get full boost back. Scan and check for KR when you make that run.
Thread Starter
Senior Member
True Car Nut
Joined: Jan 2003
Posts: 7,099
Likes: 0
From: Bonney Lake/Ellensburg, Washington- WCBF '04, '05, '06, '07 Survivor-

Originally Posted by willwren
Need to see if the BCA and BCS are working properly. Superchargers don't produce low boost unless they lose their coating, and Gen2 superchargers don't have coating. It'* either belt slip or a vacuum leak or a bad component (BCA or BCS).
John, do the Bypass trick and see if you get full boost back. Scan and check for KR when you make that run.
John, do the Bypass trick and see if you get full boost back. Scan and check for KR when you make that run.
Senior Member
True Car Nut
Joined: May 2003
Posts: 8,135
Likes: 1
From: Lethbridge, Alberta, _______Canada._______ West Coast Bonneville Fest ___05,06,07 Survivor___

I dont know, but mine would connect NOW, and with alot of force, and spin em like it was nothing at all...How hot is it outside?
As far as I know, there is no check valve on the vacuum line to the modulator on ours, at least not on mine. Like Bill said, pull the vacuum elbow between the BCA and BCS off and see if your boost returns.
And try this: with it idling, pull the vac line off the top of the BCA. Does the rod push all the way out so the foot hits the base of the SC? Be prepared to put the line back on, it may rev, I've never done it myself.
And try this: with it idling, pull the vac line off the top of the BCA. Does the rod push all the way out so the foot hits the base of the SC? Be prepared to put the line back on, it may rev, I've never done it myself.
John called while on the freeway. I made him pull over and get out. 
Looks like the BCA won't full-travel in either direction. He'* going to remove it, clean it, and lubricate it. Hopefully tomorrow.
Looks like the BCA won't full-travel in either direction. He'* going to remove it, clean it, and lubricate it. Hopefully tomorrow.





