idle problem

Idle problem: Starts and runs just fine, but after the engine warms up, it seems to miss. Sometimes it will die when at idle. When the AC is on it gets worse. when I press the gas, it runs great.

I changed plugs and wires about 2 years ago. The truck is 25 years old and not driven very much but has always been a pretty good vehicle. Any ideas? _____________________________________________

Possible carb needle valve leak (dirty jet or weak float). Runs okay cold with rich mixture and fast idle. Runs poorly at slower warm idle because mixture is too rich. Runs fine when floored and throttle airflow leans it out.

Good luck.

Rodan.

Idle problem: Starts and runs just fine, but after the engine warms up, it seems to miss. Sometimes it will die when at idle. When the AC is on it gets worse. when I press the gas, it runs great.

I changed plugs and wires about 2 years ago. The truck is 25 years old and not driven very much but has always been a pretty good vehicle. Any ideas? _____________________________________________

Possible carb IDLE JET NEEDLE VALVE misadjusted rich.

Possible carb FLOAT VALVE leak (dirty seat or weak float).

Either condition can cause a rich fuel mixture, where the engine runs okay cold at fast idle, runs poorly at slower warm idle and runs fine when the throttle is floored.

Good luck.

Rodan.