Anyone out there have any issues with loosing boost. I have a UD 1400 with a Hino in it. The truck starts and idles fine, but when you drive it the engine light will come on and you loose boost. If the truck is shut off and turned back on, the light will be off. Drive it again and it will come back on. This doesn't happen at low rpm's. It seems to be triggered when coming down off of 2500 - 3000 rpm's. I also notice that the temp light will shoot up and then come down at times, not necessarily in unison. Any ideas to correct the situation would be greatly appreciated.