Is this normal? Finally got to the 150k valve adjustment on Saturday and now it starts beautifully when cold once more..did a double take and checked it twice but with 290k on the odometer, the timing is right on the mark. Its the original chain..am I just plain lucky or do they actually last this long? Based on all of the related posts, I had expected to have to replace it.

On another note, the vaccuum switch gizmo on the top of the valve cover..what does it do? The two piston pins on the actual valve/switch..it looks like the little plastic "flappers" used to extend under the pins when new and acted as part of the actuator. These look like they just plain wore off (there's just thin little plastic stubs left) so now the pins just ride on the plastic cam (which is starting to develop grooves). If so, it means the pins don't get pushed up as far. Is my hunch correct and would such wear affect anything?

Thanks and Happy Holidays..

MikeL

84 300 CDT