Low power on startup seems fine once get going

[Ron Davis]

Context.....
So CAT bypassed the fuel water separator, and fuel filter changed around 700 miles ago.  However when I pulled into RV park couple nights ago the fuel filter seal had exposed itself and was spewing diesel .....suspect it was poorly tightened and the 400 miles that day in the i25 and i40 hills thru Albuquerque pushed it over limit.   Refit the seal and tighten and seems good...at least for now....  also had a coolant leak from an approx 1inch hose just behind the larger 2 inch one on top of engine.   I have fixed and secured that.  We are all dry now... but response to throttle seems sluggish ... has happen off n on before but noticeable if not warmed up to over 150 degrees.

My next bets are the air filter, or even replace fuel filter again due to possible particles in the fuel tank. 

She also has what I call a small hiccup after starting about every 45 to 60 seconds, like heartbeat that skips a beat on occasion.  No codes that I see on the console. 

Thinking to take backroads vs the freeways or a while in effort to reduce load, but the stop n go of towns seems will not help in that effort.

Thoughts anyone.

Thanks
Ron

[Eric Maclean]

Ron
There is a short period of time after initial start up that the engines ECM  runs in a derate mode to allow the engine to warm up before it will allow for full torque output during this time you will perceive very little throttle response this is programed into the ECM to avoid engine damage caused by not warming up enough.

If your problem carries on after the engine has reached operating temperature is be checking for air in the fuel exiting the cylinder head ( return line) it is quite possible that you are getting air infiltration at the Mornings of the Favor full separator sight glass .
There are many posts here on the forum about this issue do a search to see them

Hope this helps
Eric