I posted a problem early this month re: Volvo Diesel not comming up to full RPM. Two of four delivery plunger springs in the injection pump were broken. Each plunger has a spring that builds the pressure to send the fuel to the injectors. When dealer took off the injectors, they found evidence of water damage. They suspect that someone in the past used an alcohol based fuel additive that allowed water to bypass the primary Racor fuel/water separator. The alcohol absorbs water in the tank and releases it in the injection pump. Once the water was in the injection pump it weakened the springs. My engine uses a Bosch VE pump originally developed for VW diesels. The dealer recommened running a fuel additive called Stanadyne. They are starting to see problems with injection systems as the oil companies are removing more sulfur from the fuel. Sulfur used to run in the thousands of parts per million. A couple of years ago they released low sulfur fuel at about 500 ppm. Late last year some companies started producing 50 ppm sulfur content. While the sulfur doesn’t help a diesel run, the process by which they remove it from the fuel affects its lubricating qualities.