Hello all. I have a 2006 Blue Bird with a CAT C7 ACERT engine in it and it has 180,000 miles on it. What is happening is while driving the bus it will intermittently experience a miss/low power type situation. Never has the check engine light came on. The engine starts to run rough and a severe lack of power, as in it will not even pull itself on flat land. NO CEL. At first I though it was fuel filters as it was due for a service anyway. So I serviced it changed both fuel filters and sent it on its way. it ran for a couple days and it did this again. I changed fuel filters a second time and took it for a test drive. it made it three days this time and started running poorly again. Even in neutral if you floor it the rpms will not go over 1500 and it has a noticeable miss. I have swapped the HEUI oil pump with a known good running engine. Same results, runs for a few days then it starts doing this miss/low power stuff. Now I left the dog house off and when it is doing this if I unplug the HEUI pump the engine runs smoother but does not gain any RPM. Any one here ran into this before? I have a few more ideas and thoughts like run it out a bucket of fuel perhaps there is an issue with tank, lines, ETC. Also thinking fuel injectors maybe but I should be getting a check engine light. Can timing sensors go bad and not throw the CEL?
Yes those sensors can go bad and not through a code. However since you change filters and it runs good for a couple of days, cut open the filters and look inside.
2006 C7 ACERT
Posted - 04/16/2019 : 11:37:54 AM
