Dumb Question

[KKneipper]

Does adjusting the BISS screw on the throttle body affect air flow, fuel flow, or both? Just curious and searching didn't come with any results for me.

 

[steve]

Air flow bypassing the throttle butterfly. The BISS, ISC, and the FIAV are all parallel bypasses around the throttle plate in the throttle body.

 

[talon_tempers]

I have always thought there was no such thing as a dumb question. if you do not know then ask . knowledge is power.

 

[LiquidX]

As Steve said it affects airflow around the butterfly plate in the throttle body. The BISS is used for setting you idle and is short for Base Idle Set Screw.

 

[ist dwa]

Air/fuel adjustements are made based on the MAS readings, so simply put no it doesn't affect anything other than idle.

 

[KKneipper]

Nice, I've been wondering about that. Thanks.

 

[DSM1G90]

When I got my DSM, I had no BISS screw in the thing, but there was a plug covering that hole to seal.

Before I finally got a BISS screw, the thing held was holding RPM at 750, but when I had to get my ECU rebuilt, I was told that I really need to get that screw so the system can work better since the ISC wasn't working as it should since no BISS screw was in place.

Thus, I did - still hold 750RPM and the system likes me better by starting up greater and better performance.

 

[AlaskanDsm]

Remember, before adjusting, to ground out the two connectors to set base idle.

1G BISS Adjustment

 

[KKneipper]

What should my 2g auto tranny be idling at when it's up to normal temp and it's in neutral? I'm only idling at 500-550, and I know that's too low, but I don't want to set it too high either.

VFAQ said 1g manual tranny should idle at 750, but I don't know if thats different for an auto...

 

[cfeyhris]

What should my 2g auto tranny be idling at when it's up to normal temp and it's in neutral? I'm only idling at 500-550, and I know that's too low, but I don't want to set it too high either.

VFAQ said 1g manual tranny should idle at 750, but I don't know if thats different for an auto...

i would check your seals around the intake, and make a little adjustment to your throttle screw