I just got access to a HP Tuner and am trying to learn a little about it. I found the balance rate PID's for each cylinder, and I've suspected having bad injectors since I purchased this truck. It seems very sluggish to my last D-Max, (although it was a LLY and I now have a LB7).

I'd sure appreciate if anyone smarter than me on this stuff that could look this over and see if it looks like I have a problem. If I need to re-scan and monitor different parameters, just let me know and I can re-post that.

I can also email the .hpl file to anyone that would like to check it out, but it won't let me post it here. Thanks,

TravisT

Balance rate spec is +/- 4 in Park and +/- 6 in Drive (brake set) with the engine idling.. Your #6 cylinder (Column R in your spreadsheet) is greater than 4. If this data was taken with the engine idling in park then it's just over the spec.

Just checked these again to make sure I had good readings. I noted that my rates were higher in park than in drive. Are the specs you posted backwards, being +/- 4 in gear and +/- 6 in park?

Travis, Balance rate specs are as I posted ... Park: +/- 4 ... Drive: +/- 6 .. try a forum search for more info .. whenever i check mine the values are higher in drive

Travis, Balance rate specs are as I posted ... Park: +/- 4 ... Drive: +/- 6 .. try a forum search for more info .. whenever i check mine the values are higher in drive

x2

I wonder if that indicates anything. I guess I don't understand what the balance rates exactly mean, but mine seem to creep up to about 6 in park and 4-5 in gear. By the way, you said brake set in drive - do you mean parking brake or does it matter? When I checked it, that was with my foot on the brake. I know the power brakes put a load on the engine, maybe that is affecting the results?

Power brakes. Not sure if it's to add load or just because the truck is in drive...my guess would because the truck is in drive and the parking brake isn't designed to hold the truck still against the motor.

Is it smoking at idle or have a rough idle?

Regarding Balance rates Here's a snip from the GM "Fuel Injector Balance Test with Tech 2" Service Procedure (796346)

"The balance rate adjustments are utilized by the ECM only at idle. The balance rates are the fuel adjustments for each individual cylinder based on the variations in engine crankshaft speed. A positive value indicates that fuel is being added to each cylinder event, such as with poor engine compression or a fuel injector that is not flowing enough fuel. A negative value indicates fuel being removed from each cylinder event, such as a fuel injector that is flowing too much fuel. The balance rates will change depending on if the transmission is in Neutral or Drive.
This step determines if the ECM can control a stable fuel pressure. A high balance rate may be caused by a fuel injector or compression only if the ECM can control fuel pressure."