Friend of mine has 92 ctd 4by 4 . Was running rough with a slower idle. On the highway it was running good, when he got it home it died in the yard when he slowed down after driving a couple hours. It started once after that, ran about ten seconds, then quit. Would not start since. There is fuel from the lift pump to the inj pump, how much pressure does the lift pump have to put out to be picked up by the inj pump? Could it be the lift pump?. The fuel filter was changed, with rusty looking stuff inside the filter. What are the symptoms of a inj pump going ?