CM2250 Poor fuel mileage

[Truckdriven]

(03-01-2022 )stevegrutz Wrote:  I ran into a truck that was tuned by rr. It was getting horrible fuel mileage, still drove fine but had a hunting kind of rough hi idle. After various tests and data logging i realized the turbo speed rpm was 0 while running. Found a broken wire for the turbo speed sensor, and now the truck is running great again. It was also a cm2250 and it threw 0 fault codes for the problem.

Interesting..... Just tonight I was at the back of the trailer when he started it and after maybe 30 seconds or a minute it started doing the hunting thing at idle, it was subtle and probably would be missed by many people but was immediately obvious to me. I had caught it doing it once before but when I asked the regular driver he didn't know anything and I thought next I was just confusing it with another truck, now I know it did it, but it only does it occasionally. Gives Me one more thing to investigate.