Sai pump makes wierd sound
Mudding
Joined: Jan 2012
Posts: 125
Likes: 2
From: Langley B.C.
I'm a little leery as they are re-built.
My Father's word keep ringing in my head, "If it seems too good to be true......."
I suppose it is only $150.00. If it works and holds out then great. If it dies within a year, well, it was only $150.00.......... Hopefully they would stick to their 2 year warranty!
I'll pick one up and see how it holds out.
My Father's word keep ringing in my head, "If it seems too good to be true......."
I suppose it is only $150.00. If it works and holds out then great. If it dies within a year, well, it was only $150.00.......... Hopefully they would stick to their 2 year warranty!
I'll pick one up and see how it holds out.
Super Moderator
Joined: Jan 2011
Posts: 16,322
Likes: 88
From: Savannah Georgia
If we take these notes from the RAVE as facts:
The engine coolant temperature must be below 55 °C (131°F) for the SAI pump to run.
So it probably should not be running, but could be based on flakey O2 sensors and/or grounded wiring.
The engine coolant temperature must be below 55 °C (131°F) for the SAI pump to run.
NOTE: The ambient air temperature must also be above 8°C (46°F) for the SAI pump to run.
The pump is electrically powered from a 12V battery supply via a dedicated relay and supplies approximately 35kg/hr of air when the vehicle is at idle in Neutral/Park on a start from 20°C (68°F).
Then I would guess it should not be normally except as in note below. If the relay in under hood fuse box is bad, or if the black/orange wire from the relay coil is melted/skinned somewhere and touching a ground it could make relay pull in. See RAVE circuits diagrams and connector layouts, there are plugs under fuse box to be wiggled.
From the Bosch ECU manual, this blurb about test of the pump, when running, if O2s don't provide enough feedback:
Diagnosis of the secondary air injection system can take place in two steps. There is a passive diagnostic which checks for a lean shift in the signals
from the front oxygen sensors during secondary air injection operation and there is an active check, which only runs if the passive check fails to
achieve sufficient test results in any drive cycle. The active test has two parts; firstly the secondary air injection pump will be run with the control
valves shut. If the valves are leaking or stuck open, the feedback fuelling will shift lean and a fault will be detected. If the valve check is passed, then
the valves will be opened and if sufficient secondary airflow exists, then the fuelling will be shifted lean. If the lean shift is less than the required threshold, then a fault is stored.
from the front oxygen sensors during secondary air injection operation and there is an active check, which only runs if the passive check fails to
achieve sufficient test results in any drive cycle. The active test has two parts; firstly the secondary air injection pump will be run with the control
valves shut. If the valves are leaking or stuck open, the feedback fuelling will shift lean and a fault will be detected. If the valve check is passed, then
the valves will be opened and if sufficient secondary airflow exists, then the fuelling will be shifted lean. If the lean shift is less than the required threshold, then a fault is stored.
So it probably should not be running, but could be based on flakey O2 sensors and/or grounded wiring.
Last edited by Savannah Buzz; Aug 25, 2012 at 09:35 PM.
Recovery Vehicle
Joined: Feb 2011
Posts: 1,027
Likes: 1
From: Wabash
I have a period of a few weeks where it would turn on for no apparent reason while I was already 200F+ in coolant temps... it only happened I noticed after awhile, when I came to a sharper then normal stop, and it would stop or go away if I moved again. I chalked it up to ****ty wiring like everything else... i jiggled the harness around like I normally do when I get codes hahaha and it worked, hasnt happened again since.
Mudding
Joined: Jan 2012
Posts: 125
Likes: 2
From: Langley B.C.
I haven't purchased a pump yet, I've been away on vacation.
Most of the websites selling replacement pumps show a Discovery II Pump for 99-2002 and a different one for 2003-2004 - The dealer says they are different pumps for the model years above.....
These re-built models show 99-2003..... The website owner says they are all the same, but I'll do some more research on the specific differences before I shell out for the potentially wrong part.
Most of the websites selling replacement pumps show a Discovery II Pump for 99-2002 and a different one for 2003-2004 - The dealer says they are different pumps for the model years above.....
These re-built models show 99-2003..... The website owner says they are all the same, but I'll do some more research on the specific differences before I shell out for the potentially wrong part.
