5.9 Cummins
I have a 2002 Bluebird CSFE 2409 transit style bus. It has the 5.9 cummins ISB with the Allison 545 tranny. When I start it up cold it has an odd habit of ramping up the rpms on it's own and also sounds funny, almost like a compressor knock sound. If you kick the throttle it will idle down. However it will ramp back up on it's own in a few minutes. The knocking sound goes away after the first time. It is not the compressor that is knocking. I checked. It will continue to ramp up the idle until it decides it is warm enough no matter how many times you kick it down with the throttle. The colder it is the more it does it. I have tried to overide it with high idle switch, but it will shutdown the high idle and ramp up on it's own sometimes. I was wondering if anyone had experienced this before or knew something about it. The bus has low miles and is in good shape overall. It starts very easy and smokes only a tiny bit until it starts to warm up. It has good power when driving so I do not believe it is a big deal. I was just curious thats all.
__________________
Eric A. Hinkley
|