i havent checked the fuel filters, but right now the ignition is all messed up, so the engine wont even turn over. i just had my dad's friend fix it 3 days ago, and the ignition got messed up again. i think he made a temporary, cheap fix to it. it makes me mad, because it hasnt run nearly all winter. every great once in a while, i'll try to start it, and it'll start. i know that i need to get it towed somewhere to a diesel mechanic shop and get the ignition fixed, and i'm thinking about getting all the wiring fixed also while it's there. the engine was put in before i bought it, by a guy that did a really sloppy wiring job. anyway, since its been warm, the 2 or 3 times that the ignition has actually worked, it started and ran fine.