190e erratic idle
I own a 1986 190e, 8 valve gas. It starts easy and runs smooth until it warms up. After it gets warm the idle begins swinging from about 300 rpms to 1000 rpms. It is still running smooth at this point, its just that the idle is swinging up and down. Can anyone give me some probable causes and tests to confirm the cause? Any help will be appreciated.