The idle is adjustable at the pump stop. The rythmic oscillation type of idle is often caused by TOO much idle. To test if this is so just lightly push the "STOP" link till you have reduced the idle to various speeds. Also the vehicle tach isn't suitable to establish proper speed. The oscillation type of lope also is to be dampened by the proper adjustment of the rack dampener on the back face of the inj pump. Twelve wrench bolt with 14mm jam nut. This is too be screwed til it just dampens the oscillation.
Most are screwed in too far which causes motors to start and die when cold.
Another problem that is fairly easy to fix is fuel line bleed back through the pump element check valve seals. This leak-down causes the quantity of delivery to be different from cylinder to cylinder and a rough idle is a result...it can get worse. The seals are a flat copper washer. They can be changed on pumps that don't have external mixture correction on the elements.
[This message has been edited by Webmaster (edited 03-16-2000).]