Engine stumbles around 2000 RPM

[woof]

I have had this intermittent problem for several years. Recently it has become more annoying. Around 2k the motor "misses" at cruising with a light load. I can get right by it by putting my foot in it but 2k is unfortunately Freeway speed and hard to avoid...If I set cruise control at that exact speed the engine purrs. I suspect APPS and my banks exhaust brake but after having a local "high performance" shop check it there were no codes. They tested my injectors and replaced all 6 for $3400 but no affect on my problem. I finally got that Bill paid off and am ready to do more investigating. Hopefully doing the work myself. I should mention the exhaust brake works intermittently as well.
The truck now has 193,000 miles. The shop disconnected my banks stuff and for now is still disconnected, I'm sure they will hook it back up for free (they did feel bad ,but they also did charge me)
Thank you all who take an interest in this. I hope this is the proper forum for this post. Also would love to find a good mechanic, I am just over the Columbia river from Portland, Or in SW Washington
Thanks again
Steve Wolfe

 

[wildbill]

First thing, are there any codes?

Not sure if it still holds water, but you can reset the APPS on the 03-05's. All you do is turn the key to the on position, but don't start. Slowly depress the accelerator pedal and hold it for a few seconds. Slowly release the pedal, turn the key off, then start the truck.

If it helps, but does it again, it'll need replaced. It could also be the fuel regulator, a faulty rail pressure sensor or a bad injector.

 

[SuperSteeler]

My 2004.5 did that early on after I bought it. A reflash by the dealer fixed the problem (I think there was a TSB issued for it). They put a sticker under hood saying it was done and the number it addressed but I'm pretty sure the ink has faded since then.

 

[cerberusiam]

The APPS reset is useless on a 3rd gen, the APPS recalibrates itself at key-on. Depending on what APPS you have it might be it but you SHOULD have codes indicating an issues. If you have the one under the driver side battery the connection is suspect as they get a lot of garbage on them, as opposed to getting vibrated to death on the engine. Might want to check all the battery cables, grounds, clamps for corrosion or problems. A "miss" sounds more like an electrical issue than anything.

 

[woof]

Thank you. I will try the reset just in case and then locate the apps and check and clean the connections. The only codes I have gotten have been crankshaft position sensor and I replaced that. I believe the banks brake wiring splices into the apps so I Wil try to find that too.
Thanks for the suggestions.