occasional misfire

I need some help with this irritating problem. My '08 FTLR, 14L DD60 purrs like a kitten - most of the time, good power, 8mpg. Then it'll start hesitating, then it'll misfire, then it'll misfire really badly, then it'll lose power and drop up to 25mph before kicking back in, buck and snort like an old, pissed off mule. It hasn't stopped on the road yet, but sometimes it's really bad. Then it'll run perfect for a few days. It does not throw codes, so the shops are pretty much helpless.

I have spent a lot of time on this in the last 2 years, and a considerable amount of earned income. New DPF harness, intake throttle valve, one injector once, then a power pack recently, changed out my DPF filter and cooling system, new injector harness (Freightliners have this annoying issue with the injector harness leaking oil and having the oil seep down into the ECM - not a preferred behavior).

All of these repairs have solved the hesitating/misfiring for a few days, a week, then it creeps back. Can anyone offer some trucker wisdom for me? I could really be happier without this irritating, recurring problem.

Note: When the truck is mis-behaving, it'll blow smoke from the stack when it misfires, and it occasionally pops out of the stack, and a blows a small cloud when that happens. When it's misbehaving, it's really crappy, jerky and erratic at slow speed operations, loading/uncoupling, parking lot, fuel island, so on. Thanks

 

Just had a power pack (6 new injectors) installed. Was perfect for about a week or two, Old School. I still think that's involved. It seems to happen more during a passive regen?

 

Yes, Pete, still having the issue. Truck has been running well for about a week, and I'm home now for a while, working on my rental unit, which was trashed by some trashy people. Again, dang it.

My problem is tough for shop staff. Intermittent, doesn't throw any codes, kind of a pain.

What's your interest, if I may ask? J

 

I'm happy for you, Pete, and I'll watch for your news. However, I'm still looking for my cause. Funny, the last 4 days I was running, on my way to Rio Rancho (home) truck purred like a kitten. I keep hoping something fell or was pushed into place and the ol' DD60 will be content to run good for a while.