i have a 68 coup with a 390 4bbl. after i turn the ignition off the engine keeps running sometimes. not always. what cuases this and how do i correct it?

 

The most common cause is that the engine idle is set too high. Idle for a 4 speed manual should be about 625 and for an automatic around 750. If your idle is set properly then you might look at your timing to see where it is set. It may be too retarded or advanced. Next, an ignition switch that has worn contacts can cause a delay in cutting off the ignition even though the key was turned. Hope this helps some.

Dave

 

thank you very much. appriciate the advise