Hope this is the right place to post, first post!
I am having an issue with an '89 Shamrock with a cummins 6bt that is baffling me. At idle up to cruising rpm
sounds and runs just fine, however, if you try to go above 2200 rpm
through to open throttle the engine
sounds like it is derating until it comes back to normal operating rpm. Any adjustment to throttle increase has the same effect. Coming from a tractor trailer background of diesel
repair i can only describe it as this...if you try to go wide open throttle the engine will accel normally until just out of the rpm range you are trying to achieve. Just before it hits, the engine sounds like an engine brake is being applied for about 2 seconds, then comes back to normal rpm's until a throttle change is made. It only does this at high rpm's. I do not know if it is a fuel
or boost issue. Where do i begin trying to figure this out. I am used to Mack and Mercedes engines, this cummins has me scratching my head
thanks in advance for any advice