Questions on Balance rates...

Per the following description of balance rates quoted from the Sept04 GMTechLink, when the balance rate for a given cylinder is positive does that mean it is getting extra fuel? Also, would an over limit positive balance rate indicate the injector is leaking or returning too much fuel? Or is the sign (+/-) of the balance rate not significant?

"Balancing Rates
Normal fuel delivery to each cylinder is around 1 cubic millimeter (mm3) for the pilot injection and 7 mm3 for the main injection. The balancing rates are the measurements of the amount of fuel removed from or added to these normal fuel quantities during each combustion event.

Balancing rates are available and accurate only during stable idle. These numbers tell you whether or not you have a possible compression, injector control, or injector issue.

Once the misfire is detected, the balancing rate of the cylinder that has the misfire will be as high as 15 mm3. The misfire codes (P0300, P0301-P0308) will set only after the first 90 seconds on Federal LB7s (30 seconds on California LB7) of engine operation and will set only when the balancing rate goes above 15 mm3.

The normal values that should be seen on the balancing rate parameters will range between -4.0 and +4.0 in Neutral or Park (-6.0 to +6.0 in Drive when the brake is fully applied). Suspect a possible problem when the balancing rate of a particular cylinder starts to increase out of the normal operating range. An example of a possible problem cylinder would be a balancing rate of 7 mm3 or so. Once the numbers start to increase out of the normal range, the cylinder is progressively contributing less power than the other cylinders."

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