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need help adjusting biss screw

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TheRealist

15+ Year Contributor
464
3
Dec 12, 2005
Chula Vista, California
Anyone know how to adjust it, i mean i do using a screw driver, but my car seems off a little... i completely closed it going clock wise and it a little ruff but stays on... now going counter clock wise, haveing good idle how many turns to turn ect... or it doesnt work like that? when adjusting is there anything to hear for when its adjusted right? ect ect..
 
If you have a pocketlogger, a really easy way to adjust it is to watch your ISC steps and turn the screw. When your ISC reads 20 steps, you have sucessfully adjusted your BISS.
 
The BISS isn't like a idle needle on a carb. It only adjusts the amount of air bypassing the closed throttle plate at idle. This is in addition to the air bypassed by the ISC.

The correct way to adjust on a 2G is to use the MUTT (dealership scan tool) to lock the ISC to it's default position and then adjust the BISS for a 750 RPM idle. I don't know if any OBD II dataloggers/scan tools allow monitoring ISC steps other than DSMLink but if they did you could adjust the BISS until the steps were 10-20. Without either of these you can't correctly adjust it becasue of the interaction between the ECU trying to hold a 750 idle using the ISC and the BISS.

Steve
 
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