If the idle solenoid is controlled by AC on/off ;Does this mean that the idle is not computer controlled on my LG4 engine? This will make adjustment easier....

If the sparkplugs are going bad/old; Would they perform bad when the engine is cold, and better after the engine becomes warm?

 

The idle is a mechanical adjustment on the side of the carb. See the pictures in the post about needing a carb diagram.

The "high idle" comes in two parts: the choke high idle, which is located on the bottom of the carb, opposite side from the main idle adjustment, adjusted from the back; and AC solenoid adjustment, where you turn the hex bolt sticking out of the solenoid while engaged to adjust the idle speed.

I swear the solenoid will engage during certain de-acceleration events, which would indicate there is a computer involvement as well, but I've never traced down that circuit to verify.

As for the plugs: It is possible they don't work as well cold as when the engine is warmed up. The mixture is a little easier to ignite when the engine is at operating temperature.