I think this is a Daewoo truck with a Puegot engine. They were real turkeys on power to start with. If you can push the button all the way in with no change, replace the converter. They are $100 here in the lower 48. Converters generally only last 5 to 8 years. If you are short on cash and have time to burn, they are easy to rebuild. I think a rebuild kit is only about $30. Nobody rebuilds because a complete new one is is cheap as paying me the labor and parts to rebuild one.