ISL not performing
OK you diesel experts, here's what's going on. I have a 400HP Cummins ISL in a 2005 Itasca Horizon motor home. I've had this coach for 3 years and it's performed flawlessly. Last winter I had a diesel guy in our RV park change the oil and all the filters. Upon leaving the park to travel home, the coach right away wasn't showing any power. In the past it would rev right up the the 2000s before shifting and it would pull like crazy. Now it just has no guts and it shifts at 1000 to 1500 rpm. It seems to run OK once up to speed. it will still cruise at 65 with the cruise control on, but if it meets a big hill it just dies. Stomping on the pedal has no effect, as if it isn't even connected. Also, I don't know if this is connected or not, but the turbo gauge jumps from mid-gauge (0-25) right to the max. (50) when the engine calls for power. I don't remember it doing this in the past, but then again I don't remember looking at it that closely when it was running fine. I actually stopped at a Cummins South service center on the way home last winter, but they said if it ran at speed and showed no trouble lights then it was probably OK. Although it does what they said, it's definitely not OK. Any ideas?
