My fj60 knocks under load, and on hill starts. Just did a valve adjust, new plugs, etc. Everything seems right, so I'm trying to get the timing so that I don't knock anymore. Can't seem to however...
I've removed and plugged the vacuum advance lines to the dizzy, and with it adjusted so that the bb is exactly under the pointer, it knocks. (Vacuum at this point is 21.5 inches by the way - for those of you who've suggested timing by vacuum).
I've retarded the timing, bit by bit. Now the bb has moved to be just under the edge of the window, and vacuum is 20 inches. Knocking still on hill starts, and just a little rattle under load at higher rpm.
From reading the FSM and Haynes the only thing that I can think of is that the pistons are carbonized, due to many miles with a carb running rich. Right solution would be to have the carb rebuilt, and to yank the head to clean the pistons.
However, I don't know enough about engine tune-up/timing/etc to spend this kind of money and time w/out some smarter folks chiming in first...
Any advice appreciated.
I've removed and plugged the vacuum advance lines to the dizzy, and with it adjusted so that the bb is exactly under the pointer, it knocks. (Vacuum at this point is 21.5 inches by the way - for those of you who've suggested timing by vacuum).
I've retarded the timing, bit by bit. Now the bb has moved to be just under the edge of the window, and vacuum is 20 inches. Knocking still on hill starts, and just a little rattle under load at higher rpm.
From reading the FSM and Haynes the only thing that I can think of is that the pistons are carbonized, due to many miles with a carb running rich. Right solution would be to have the carb rebuilt, and to yank the head to clean the pistons.
However, I don't know enough about engine tune-up/timing/etc to spend this kind of money and time w/out some smarter folks chiming in first...
Any advice appreciated.