My old truck at work wouldn't start a couple of weeks ago. It has a N14 Cummins engine in a 1998 model truck. They found that the rubber fuel lines from the tank had deteriorated and plugged the fuel cooler. It's a strange animal. At first I thought it was for cooling the fuel but that is not he case. It's about the size of an encyclopedia book but only about 1/2" thick. Seems to be made of aluminum and is hollow. A fuel line is hooked to each side and it is bolted in between the ECM and the engine block. It's supposed to keep the ECM cool. Pricey, it runs about $700 list. It's hooked in before the filter. By the time I got a chance to take a picture of the old one it disappeared.

About 2 weeks later I refused to start again. This time the injector pump took a dump. I'm wondering, do you suppose the restriction caused by the plugged cooler might have damaged the pump like can happen with a VP44? If so the moral of this story is replace the rubber fuel lines before you get 843,000 miles on your engine.