Bucking-Fishbite Under Load- Again and Ongoing

[BrentN]

Robin,
Thanks for the input. The injectors were replaced about 75k ago. The engine actually only has about 90k on it, as GM replaced it just before I purchased it.

I was able to spend some time yesterday on it. I had replaced the filter last fall and the truck sat most of the winter. I had been quick to ASSUME the filter was still good having "just" replaced it.

I took DmaxMavericks advice and put a sample of fuel into a clear mason jar. What looked clean and green out of the hose turned murky and had floatys in it...algae.

I popped the "recent" filter to find it brown and coated with crap- Photos below. The Fuel manager bowl had a bunch of black algae in it. Which took some time to clean.

I put some Power Service Diesel Clean into the tank, replaced the filter, cleaned the housing as well as pulled the IP inlet strainer and made sure it wasnt plugged.

Went out to Spirit Mountain today from Salem and Zero performance problems. It felt like one fishbite bump on the way but the engine ran great except for that. Power was back in full force.

I am planning on running the remainder of the tank of fuel out and drop the tank in the next week or two and give it a good scrubbing as well as blow lines and swap filters and clean the bowl again. I am sure there is still more in the system, but needed to drive the Burb today.

From my reading it was enlightening to find that algae is on the rise with the 2007 change in sulfur content in diesel. Apparently the sulfer helped abate algae in the past.
Knowing this, I need to go get some algaecide dumped into my 150 gallon tank on my diesel pusher. It sits all winter as well.

In the photos below...The cloudy jar is before replacing the filter and the clear jar is after. Pretty stark. These sat in the sun for a few hours.
In the single jar photo, you can barely see the fuzzys in the bottom of the jar, but you could definitely see clear looking stuff floating in solution as the diesel was going into the jar.

Like Dmax advised...check the basics...I would have bet my life that my filter was clean since I had replaced it last fall.

I do appreciate everyones help. Have a great Easter