Hey Forum folks...

In my 67, when I shut the car off, I get pre-ignition shudder for about 5 seconds and then a whooshing noise like a release of either air or liquid...could be many things evidently... anybody out there experience this and what it turned out to be?

 

I drag the clutch when turning key off. This stops run on.

 

The run on resulted in the engine running backwards instead of sucking it was blowing. clutch kill it.

 

Guys... understand that the clutch kill will stop it...but what are the likely reasons it's happening so that I can fix it? Thanks, Rob

 

If the carburetor has an idle stop solenoid then it may be sticking and not allow the throttle plates to completely close on shut off. Another cause could be running a spark plug that's a grade or two too hot and you're getting preignition from that. Also the engine may be running too hot.

 

Thanks Shark...need to check the carb and plugs...