Engine/Transmission (1994 - 1998) no more air, but still running rough

[wrichards]

1998 12 valve chassis cab I changed out the fuel lines with larry b's so there should be no air in my system. Lift pump was from genos installed last january. Engine runs rough almost like it is out of balance. It has 138 k on it and valves not adjusted since 50 k, would that make it run rough? also has most everything else original so would injectors help? thanks

 

[GAmes]

It is a fairly easy job to adjust the valves, and doesn't cost anything but time. Give it a shot, can't hurt. Injectors should be fine with only 138k. Take a few minutes to inspect the damper. Time might have caused the bonded rubber to deteriorate.

 

[Joseph Donnelly]

Did you clean the pre-filter screen which is next to the lift pump; its cover is on the bottom of the fuel heater module.