My 88' has 145K, have had a light knock when cold but disappears
when warmed up. Recently got a misfire feeling when in OD and under
slight load. When shifting to 3 it went away. Got stuck plowing one
day and barely made it home. Ended up changing the plugs,wires,cap
and rotor one item at a time starting in between each. Ran better each
time. Seems to be choked to much when started now and that lasts
until warmed up. Out on the road it really pings in OD or not.
If it were not for the pinging it would be its old self.
Any ideas what to check ???

thanks
chnaus

 

Did you check the timming during the parts changing? Did you get the proper heat range plugs? Did it ping before the new plugs? Check the egr valve for free movement.