Primer

That was the first thing I tried today! I noticed the smaller(primary filtration, I believe) was only half to three quarters full when I removed it. It actually ran worse after doing that, it seemed.

Hello! First post here, trying to diagnose a problem with my 1994 CH600(613 on the dash?) I'm trying to finish up my grain hauling and as of now have to stop due to intermittent rough running, stuttering, and stalling. When it's occurring, it will jump to 1000 or 1200 rpm as though you were quickly stomping on the throttle. Taking off from a stop loaded is the worst, as usually it will stall out during this stuttering. I'm not getting a engine light during this, either. Only when the truck has stalled out do I get one, and then for not very long. Several years ago(and about 7000-8000km ago) I had to replace both timing sensors in the injection pump to cure a very similar problem. Talking to the localish Mack dealer, he's saying either wiring harness or injection pump. What are your thoughts? Thank you for the help!