Balancing the throttle bodies with the Carbtune tool

[MC Hammered]

The previous owner told me he balanced the throttle bodies, however, in the interest of learning how to do this myself I purchased a Carbtune tool to help with this maintenance step.

http://podi.ca/winstontemp/vron/carbtune sept 19/IMG_4359.JPG
http://podi.ca/winstontemp/vron/carbtune sept 19/IMG_4360.JPG

The Carbtune allows you to view 4 of the TBs at the same time which I think is a big bonus in doing this maintenance vs. doing each TB individually.

http://podi.ca/winstontemp/vron/carbtune sept 19/IMG_4361.JPG

They include some small orifice tubing to make restrictors otherwise the rods bounce up and down too much to get a reading. Since I already designed an inline restrictor for the gauges I sell I chose to use that instead

http://podi.ca/winstontemp/vron/carbtune sept 19/IMG_4347.JPG
http://podi.ca/winstontemp/vron/carbtune sept 19/IMG_4348.JPG
http://podi.ca/winstontemp/vron/carbtune sept 19/IMG_4349.JPG
http://podi.ca/winstontemp/vron/carbtune sept 19/IMG_4350.JPG

Plugs on the vacuum ports removed, lines plumbed in and connected to the Carbtune

http://podi.ca/winstontemp/vron/carbtune sept 19/IMG_4352.JPG
http://podi.ca/winstontemp/vron/carbtune sept 19/IMG_4351.JPG

[MC Hammered]

This is how the first 4 throttle bodies are adjusted. From left to right it is cylinders 4,3,2,1

http://podi.ca/winstontemp/vron/carbtune sept 19/IMG_4353.JPG
http://podi.ca/winstontemp/vron/carbtune sept 19/IMG_4354.JPG

According to the BMW service manual the TB should be adjusted to 300mbar or 22.5cmHg so using a 7mm socket you tweak the adjusters to even out the readings. Turn left to reduce, turn right to increase.

http://podi.ca/winstontemp/vron/carbtune sept 19/IMG_4355.JPG

Plugs on cylinders 5 & 6 removed and put onto 1 & 2, lines from the carbtune plumbed in

http://podi.ca/winstontemp/vron/carbtune sept 19/IMG_4356.JPG

So using cylinders 3 & 4 for reference we adjust 5 & 6. From left to right 4,3,6,5

http://podi.ca/winstontemp/vron/carbtune sept 19/IMG_4357.JPG

After adjustment. The car does idle better and when I checked the tach the needle used to sit at 1000rpm, now it sits a bit below it.

http://podi.ca/winstontemp/vron/carbtune sept 19/IMG_4358.JPG