Go Back   986 Forum - The Community for Porsche Boxster & Cayman Owners > Porsche Boxster & Cayman Forums > Boxster General Discussions

Post Reply
 
LinkBack Thread Tools Display Modes
Old 06-12-2012, 06:20 AM   #1
Registered User
 
thom4782's Avatar
 
Join Date: Sep 2010
Location: Foster City CA
Posts: 1,099
Secondary Air Pump Operation

Most likely the forum has discussed this but I cannot find an answer to my specific question.

Does anyone know the trigger points for when the secondary air pump operates or not?

My understanding is the pump turns on and runs for a minute or so when two conditions are met: 1) the engine is cold and 2) the outside air temperature is below a certain value. Is this true?

Does the pump have to meet both conditions at the same time or is one enough? My pump runs whenever the engine is started cold regardless of the outside temperature.

Thanks

thom4782 is offline   Reply With Quote
Old 06-12-2012, 07:25 AM   #2
Registered User
 
Join Date: Apr 2006
Location: Boston, MA
Posts: 221
Not sure about your car as you didn't specify model year. On the newer cars (987), input signals for the SAI pump to run include coolant temp, intake air temp, altitude, and if the front O2 sensor is operating to allow closed-loop operation. All these values are part of the algorithm the DME uses and when it figures out when and how long the pump should run.

Regards,
paul...
paulv is offline   Reply With Quote
Old 06-12-2012, 03:59 PM   #3
Registered User
 
thom4782's Avatar
 
Join Date: Sep 2010
Location: Foster City CA
Posts: 1,099
My car is a 2001 S. The O2 sensors are brand new.
thom4782 is offline   Reply With Quote
Old 06-12-2012, 04:20 PM   #4
Registered User
 
bar10dah's Avatar
 
Join Date: Aug 2011
Location: Neither here, nor there...
Posts: 458
Quote:
Originally Posted by Bentley, section 02-11
The Boxster engine is equipped with a secondary air injection system which uses an electric pump to force fresh air into the exhaust system upstream of the catalytic converter during engine warm-up. By providing extra oxygen to the unburned fuel in the exhaust, hydrocarbons oxidize and carbon monoxide combines with oxygen to form carbon dioxide and water. The air injection pump stops within a specified timed interval.
Bentley doesn't go into any other detail about the SAI operation, but it seems to be tied to when the engine is started and it's below normal operating temperature, and runs for approximately 60 seconds. And it doesn't seem to care what the outside air temperature is.

bar10dah is offline   Reply With Quote
Post Reply


Thread Tools
Display Modes

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 On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -8. The time now is 12:05 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page