Slight "Dieseling" or "Run on"

[baucco]

I have a 73 Valiant with the stock 225 Slant. Just recently,when I shut down,it tends to run on a bit. What's causing this? It's never done it before?

 

[player1up]

It's typically caused by a lean condition and or retarded timing. Check for vacuum leaks around the carb, especially if it's a bbd. Now, why it would just start doing this??? who knows? could be summer heat...

 

[RustyRatRod]

I've always found the cause to be a high idle. Whether it's from a vacuum leak or an improper tune. Whatever the reason, it's usually because of a high idle.

 

[slantsixdan]

Lean mixture/vacuum leak, improper ignition timing, restricted exhaust, carboned-up combustion chambers and/or spark plugs, improper spark plugs, proper spark plugs but someone forgot to remove the metal ring washers from them before installing them so they're overheating, severely crudded-up cylinder head coolant passages, improper idle speed, improper cam timing…

What's the status of the car's EGR system?

Tune-up parts and technique suggestions in this thread. Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download.

 

[Snake]

I've always found the cause to be a high idle. Whether it's from a vacuum leak or an improper tune. Whatever the reason, it's usually because of a high idle.

High idle my 360 was doing it this year turned her down a tad perfect now.