My 69 is "dieseling" after the switch is turned off. It's not that bad, only does it for about a second but I don't want it getting worse. I drove it last night for about 40 miles round trip then shut it off and it stumbled a time or two after shut off. I then realized I didn't pull up far enought in the garage so I cranked it to ease forward and it didn't do it when I shut it back off. It just started the last couple times I have driven it. Any ideas? Thanks,