No Boost:
Thread Starter
Racer
Joined: Jul 2002
Posts: 476
Likes: 17
From: Appling GA
2018 C5 of Year Finalist
No Boost:
About a month ago I noticed my maggie was not producing boost at least according to the gage. I took the following corrective action, replaced my belts to include the one on the back of the maggie...its been on there awhile. I figured while I was replacing belts I would install the new ECS tensioner for the maggie, nice piece, and a 3.2 pulley for kicks. Got her running again today and no Boost...needle measures vacuum but never goes to more then 1Lb on the Boost side. Is there an easy way to verify if my gage is doing its job or should I be looking elsewhere?
Thanks Mike
Thanks Mike
Race Director
Joined: May 2004
Posts: 16,667
Likes: 1,209
From: Raleigh, NC
St. Jude Donor '15
About a month ago I noticed my maggie was not producing boost at least according to the gage. I took the following corrective action, replaced my belts to include the one on the back of the maggie...its been on there awhile. I figured while I was replacing belts I would install the new ECS tensioner for the maggie, nice piece, and a 3.2 pulley for kicks. Got her running again today and no Boost...needle measures vacuum but never goes to more then 1Lb on the Boost side. Is there an easy way to verify if my gage is doing its job or should I be looking elsewhere?
Thanks Mike
Thanks Mike
what kind of gauge are you using anyways?
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 78
From: Forney Texas
There is a valve on the blower with an actuator on the driver side with a vacuum hose running to it. There are other hoses going to the inlet very close to it at the front of the blower. Make sure the hoses are clear of the actuator mechanism. You won't make any boost if one of those hoses holds the bypass valve open. When you rev the motor with the hood up, you'll see that actuator moving. Make sure it has free operation. 
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 78
From: Forney Texas
Drifting
Joined: Jul 2005
Posts: 1,484
Likes: 27
From: Torrance Calif
There is a guy on the V forum that had no boost and he found that the three coupling pins (plastic) inside were sheared off.
These couple the rear pulley/to the lobes.
http://www.cadillacforums.com/forums...i-have-no.html
These couple the rear pulley/to the lobes.
http://www.cadillacforums.com/forums...i-have-no.html
Last edited by heavymetals; Aug 14, 2009 at 12:48 PM.
Melting Slicks
Joined: Jul 2007
Posts: 2,939
Likes: 7
From: Simpsonville SC
St. Jude Donor '09-'10
My car lost boost a month ago. I replaced the pulley to a smaller one thinking it will now make boost! ( I have a ProCharger). Well, I could only achieve 4 PSI no matter what I did. I took it to a shop to check out, and they did not find anything. Finally, I put my car up on ramps, and shook every hose. I found a hose loose inside the right front fender cover where one of my two intercoolers was mounted. I reattached the hose, and found out I am not pushing 10.8 PSI boost at 5K! Wow! I need to go to a larger pulley before I blow up my stock bottom end!
All this is just to say, see if there is any hose that may have come loose. Did it used to boost and then stopped? My hose had backed off just enough to let the air out, but a visual inspection could not detect it.
All this is just to say, see if there is any hose that may have come loose. Did it used to boost and then stopped? My hose had backed off just enough to let the air out, but a visual inspection could not detect it.
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Thread Starter
Racer
Joined: Jul 2002
Posts: 476
Likes: 17
From: Appling GA
2018 C5 of Year Finalist
No Boost SOLVED!
Problem solved BlownBlueZ06 had it correct a vacuum hose from the breake booster running near the right front of the maggie was causing the actuator to hang in the open position...thank goodness it was simple I have a huge smile on my face with more boost then ever with the new pully 
Thanks guys...Mike
Thanks guys...Mike
