First Post hello's!
08-17-2011, 06:12 AM
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First Post hello's!
Hello Everyone!
New to forum....from another forum looking for some MERC. 6.2 help.
I have a 07 Azure 238 with a 6.2 bravo one...143 hours...
lately I have been encountering a problem while coming down from WOT to almost neutral the engine will die/shutoff....unless I tap it back forward quickly....I am not getting any alarms yet....it idles fine in neutral after starting....goes into gear fine ....just has trouble coming back down to neutral....a fellow boater thought maybe I was coming down to neutral TOO slow????and it was activating the "switch"
Any thoughts?
Thanks in advance!
Bryan
New to forum....from another forum looking for some MERC. 6.2 help.
I have a 07 Azure 238 with a 6.2 bravo one...143 hours...
lately I have been encountering a problem while coming down from WOT to almost neutral the engine will die/shutoff....unless I tap it back forward quickly....I am not getting any alarms yet....it idles fine in neutral after starting....goes into gear fine ....just has trouble coming back down to neutral....a fellow boater thought maybe I was coming down to neutral TOO slow????and it was activating the "switch"
Any thoughts?
Thanks in advance!
Bryan
08-17-2011, 01:18 PM
#2
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I would suggest that the IAC valve is not responding fast enough to the throttle change.
The Idle Air Control valve (IAC) allows air to by-pass the closed throttle blades to stabilize the idle speed. It takes the place of having an idle speed screw on a carburetor.
If the engine starts to die, it opens to allow more air into the engine. If the engine is idling too fast it will close to allow less air.
It is controlled by the computer in conjunction with the engine speed input (from the distributor). I would say it is not opening fast enough when the throttle is closed quickly.
Sometimes it is sticky from carbon buildup. Cleaning it is the first thing that should be tried. There are special cleaning agents that can be sprayed to clean it (available at auto parts stores).
The opening and closing of the IAC can be observed with a scan tool plugged into the computer. Most Mercruiser dealers will have the scan tool.
Good Luck
Dennis
The Idle Air Control valve (IAC) allows air to by-pass the closed throttle blades to stabilize the idle speed. It takes the place of having an idle speed screw on a carburetor.
If the engine starts to die, it opens to allow more air into the engine. If the engine is idling too fast it will close to allow less air.
It is controlled by the computer in conjunction with the engine speed input (from the distributor). I would say it is not opening fast enough when the throttle is closed quickly.
Sometimes it is sticky from carbon buildup. Cleaning it is the first thing that should be tried. There are special cleaning agents that can be sprayed to clean it (available at auto parts stores).
The opening and closing of the IAC can be observed with a scan tool plugged into the computer. Most Mercruiser dealers will have the scan tool.
Good Luck
Dennis
