Effects of Unstable and Microbially Contaminated Fuel on Vehicle Operations: A Diesel Fuel Preventive Maintenance Program

During 1983, the Georgia Power Company experienced a problem that appeared to be fuel related. Specifically some of the new light duty trucks equipped with diesel engines began experiencing fuel pump failures and severely fouled filters. Analysis of fuel specimens from in-ground fuel storage tanks and the fuel filters indicated a high level of microbial activity in both areas and a destabilized fuel, which exhibited a tendency to form insolubles when heated. In addition, water found in some of the in-ground diesel storage tanks was of sufficient quantity to be of great concern. As a result of these findings the following steps were taken: (1) The in-ground diesel fuel storage tank fill pipe area was raised and a new fill pipe cap fitted with a proper seal. (2) Water and microbial sludge were pumped from the system and sampling was done to insure their removal. (3) A biocide and multifunctional fuel stability compound were added to the fuel, and subsequent tests for continuing activity were conducted. (4) A program for continuing preventive maintenance and testing was established for the entire fleet. This paper will deal with the details of the problem, identification of the source, and the corrective action taken.