two things to check 1 a restricted intake or exhaust ie: a dirty air filter or a clogged catalytic converter from an over rich condition 2 a breakdown in the secondary ignition system ie: old wires or old plugs also check for full fuel flow (a plugged fuel filter) David Teitelbaum vin 10757 -- In dmcnews@xxxxxxxxxxx, AJL521@xxxx wrote: > Hello, > > Latley I've been driving my D every day, with this nice summer weather we're > having in Chicago, and I've noticed a problem, Durring acceleration if the > pedal is more then halfway to the floor, the engine boggs out, and runs > extreamly rough, This problem gets much worse when the headlights and > cooling fans are on. I think the problem could be caused by a weak Duciller > alternator, or a combanation of bad settings, possably timing or air fuel > mixture. I also thought that the catilitic converter may be plugged. > > The muffler is going out, but Im not sure if that could contrubute to the > problem, looks like I get to look for a new muffler now. > > Any ideas would be appreciated > Andrew > > vin 4194