I have a 1983 300sd, the problem I have is I seem to run out of fuel to the engine. I start out driving just fine for about a mile or so then the speed drops to the point of about 5 mph and it will not go any faster. The engine feels like there is a shortage of fuel, lines are good, and I blew back into the tank with an air blower.

 

sorry ,I did that also, is there an electric fuel pump in the system somewhere?

 

That I know of there isn't an electric fuel pump unless it is after market. If the fuel filters didn't fix your fuel delivery problem, try checking the screen in the bottom of the tank,(supply line) it might be plugged