Need help with loping idle

[garrettg.bpd]

1800318004The truck is a 2002 with a cool air intake and 100hp injectors. I wrote a tune for it today and flash the truck. The truck lopes in dsp tunes 3,4 and 5. To was loping in all tunes. Loaded in the stock tune and all was fine. I look up the base file on the tis website for a base file from the tunefiledepot. any help will be helpful.

[Mitco39]

You gotta log it and see why its bouncing, it could be bouncing fuel pressure, bouncing timing. If your to aggressive with the changes to fueling around the idle region the truck will not be able to stabilize it.

Pretty much all the control systems on the truck are done through a PID feedback loop and if the gains are to high this is what happens. Go back to stock and make gradual smooth changes so that the gain is not overly aggressive in the idle regions that your having issues with.

For example if your microsec injection at lets say 10mm3 is 300Us. But at 11mm3 its 500Us its just way to much of a jump and the ECM will struggle to dampen this change and the result will be a bouncing issue. The same is true for rail pressure, injection amounts, boosting. Essentially anything your adjusting that is dependent on the loading of the engine.

[garrettg.bpd]

I changed all the idle areas to stock. That only fixed the base tune and dsp1. I believe it was a os problem. I rewrote the tune using the stock file from the pcm. The lope is gone but I'm have a low fuel pressure on the top end worse then the other os.

[Mitco39]

6006 is the only OS I use on the 01-02 LB7s

[garrettg.bpd]

After determining that the cp3 is weak and changed the fuel filter I loaded the tune that I listed on the forum and the lope is gone.

[killerbee]

You gotta log it and see why its bouncing, ...
Pretty much all the control systems on the truck are done through a PID feedback loop ...
For example if your microsec injection at lets say 10mm3 is 300Us. But at 11mm3 its 500Us its just way to much of a jump and the ECM will struggle...The same is true for rail pressure, .

This is what has been responsible for every non-hardware related induced lope I have accidentally created.

I do sometimes wish we had access to the process control variables in the PID algorithm.