Engine keeps running after shutoff.

[71_240Z]

I know there is a thread somewhere, but I don't know what to search on. I am sure that there is a word for the engine running a few seconds after you turn it off, but I can't recall.

Is this a timing problem or a mixture problem? A point gap problem? I have adjusted all of these recently.

Thanks.

[Go240Zags]

I've always heard it referred to as dieseling: http://en.wikipedia.org/wiki/Dieseling

[boyblunda]

Good link Gary. I have also heard it described as "running on" due to some of the same reasons in the link you posted.

I sometimes experience a similar event in my Zed when I am forced to use standard unleaded 91 octane fuel. However, if I use higher octane fuel and an additive such as Valvemaster it never happens.

[SteveJ]

I know there is a thread somewhere, but I don't know what to search on. I am sure that there is a word for the engine running a few seconds after you turn it off, but I can't recall.

Is this a timing problem or a mixture problem? A point gap problem? I have adjusted all of these recently.

Thanks.

You haven't upgrading your alternator to an internally regulated alternator, have you? I know I had problems with running on until I realized I had to put a diode in the charging circuit.

[=Enigma=]

Isn't "running on" something that women to when they get together on groups?

Seriously though, "dieseling" is the term I've always heard used. If I remember back to my high school auto shop days correctly, this is caused by a buildup of carbon in the cylinder or on the valves which remains hot enough after you shut down the engine that it causes any unburned fuel left in the cylinder to burn, keeping the engine going for a moment after you shut it off. The carbon build up is usually due to the car running too rich.