cutting out... - SaabCentral Forums
*
Home Saab Pictures Saab Classifieds Saab Dealer Listings Saab Forum Saab Forum


Go Back   SaabCentral Forums > Saab C900, 1979-1993 & '94 Convertible (C=classic) > C900 Workshop

C900 Workshop Classic 900 (1979-1993 & '94 Convertible) Technical Forum.

SaabCentral.com is the premier Saab Forum on the internet. Registered Users do not see the above ads.
Reply
 
Thread Tools Display Modes
  #1  
Old 10th February 2007
marmite marmite is offline
Senior Member
 
Join Date: Oct 2006                                                
Location: Gloucester
My Saabs: Saab 900 Carlsson
Posts: 209
Default cutting out...

Recently my car has developed a slight problem. If i have had my foot down in say 3rd gear, and i let off the gas and put in neutral, occasionally the engine will drop to real low revs and cut out. any ideas ? thanks for looking
Reply With Quote Quick reply to this message
  #2  
Old 10th February 2007
TheRedBaron's Avatar
TheRedBaron TheRedBaron is offline
Saab on the Brain!
 
Join Date: Aug 2006                                                
Location: Washington, DC
My Saabs: 1990 900 turbo
Posts: 5,779
Default

Quote:
Originally Posted by marmite
Recently my car has developed a slight problem. If i have had my foot down in say 3rd gear, and i let off the gas and put in neutral, occasionally the engine will drop to real low revs and cut out. any ideas ? thanks for looking
Does it only happen when you let off the gas after being above 2300-2500 or so rpm, and not when you are lower? If so I might suspect the BPV...
__________________
The faster you go, the more you see.
Reply With Quote Quick reply to this message
  #3  
Old 10th February 2007
marmite marmite is offline
Senior Member
 
Join Date: Oct 2006                                                
Location: Gloucester
My Saabs: Saab 900 Carlsson
Posts: 209
Default

only when falling from high revs.. what is the bpv... ?
Reply With Quote Quick reply to this message
  #4  
Old 10th February 2007
TheRedBaron's Avatar
TheRedBaron TheRedBaron is offline
Saab on the Brain!
 
Join Date: Aug 2006                                                
Location: Washington, DC
My Saabs: 1990 900 turbo
Posts: 5,779
Default

Quote:
Originally Posted by marmite
only when falling from high revs.. what is the bpv... ?
Turbo Bypass Valve - it releases air pressure from before the throttle plate when it closes (ie when you let off the gas) after being in a boost situation. It's located at the front of the engine on the left (if your looking from the front) side of the flywheel cover, attached to the rubber joint on the intake inlet on the turbo. It is kind of a pain to get to, because you have to spend a few minutes taking off all the turbo piping to get to it. It has a tube that goes over to the throttle body, and a vacuum line to the intake manifold. If you suck on the vacuum line connected to it and find it is not able to hold vacuum, it isn't operating properly - it is both leaking vacuum and not doing its job. About 60 bucks for a new oem one from eeuroparts.
__________________
The faster you go, the more you see.
Reply With Quote Quick reply to this message
  #5  
Old 10th February 2007
marmite marmite is offline
Senior Member
 
Join Date: Oct 2006                                                
Location: Gloucester
My Saabs: Saab 900 Carlsson
Posts: 209
Default

Ah, there could be a problem here. I have an atmospheric dump valve on the car and the pipe running to the inlet manifold is blocked off and also at the turbo end where the standard BOV should be situated. My atmospheric valve is situated on the new front mount intercooler piping...
Reply With Quote Quick reply to this message
  #6  
Old 10th February 2007
TheRedBaron's Avatar
TheRedBaron TheRedBaron is offline
Saab on the Brain!
 
Join Date: Aug 2006                                                
Location: Washington, DC
My Saabs: 1990 900 turbo
Posts: 5,779
Default

Quote:
Originally Posted by marmite
Ah, there could be a problem here. I have an atmospheric dump valve on the car and the pipe running to the inlet manifold is blocked off and also at the turbo end where the standard BOV should be situated. My atmospheric valve is situated on the new front mount intercooler piping...
That should be fine (it should be close to the throttle body, though) position-wise, if it has an adjustable spring I might make it a little looser and see if that helps (while still staying shut under solid boost of course).
__________________
The faster you go, the more you see.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Bookmarks

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the SaabCentral Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Display Modes

Posting Rules
You may post new threads
You may 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

Forum Jump


All times are GMT -4. The time now is 11:39 PM.



Powered by vBulletin® Copyright ©2000 - 2014, vBulletin Solutions, Inc.

top of page | sitemap | email us



copyright © 2003 - 2011 saabcentral.com, All rights reserved http://www.whiter.co.uk - valid xhtml - valid css
SaabCentral is an independently run website and is not affiliated in any way to Saab Automobile AB.


Garage Plus vBulletin Plugins by Drive Thru Online, Inc.