help my 89 307 keeps dieseling when i shut her down i replaced the anti-dieseling solenoid with no avail. i have 105k on it.

Is it running rough when you shut the car off? Or as it would normally?

Does this happen all the time or infrequently?

ny car does this very often. Anyone have any suggestions to this problem? It's very, very rough. i going to try running better octane gas i heard that helps, but any other suggestions would be appreaciated.

Is the car properly timed?

i would assume so because the car runs beautifully otherwise, i picked up a can of seafoam cleaner thinking that maybe i have excess carbon buildup. i appreciate the help

Usually, dieseling is caused by throttle plates hanging open slightly. Air needs to be shut off at shut-down or fuel can be drawn into the intake because of the airflow. This, along with any hot item in the combustion chamber such as carbon deposits or even a slight burr on the piston can ignite the charge. I'd check the carb first for proper settings and then probably run some Top Engine cleaner through the engine to eliminate any carbon.