run on ( timing question )
Melting Slicks
Joined: Oct 2000
Posts: 3,023
Likes: 2
From: TEXASTEXASTEXASTEXAS TEXASTEXASTEXASTEXAS
St. Jude Contributor
Re: run on (emsrescu)
Actually, it's my impression that run-on (deiseling) is most often caused by too high an idle speed and/or a carb fuel mixture that's not set right.
JB
JB
Pro
Joined: May 2003
Posts: 619
Likes: 0
From: winnipeg MB
Re: run on (JB)
i had run-on until i advanced my timing. it went away. Also, i know carbon in the chambers builds up and glows red hot... as a deisel. try adding a little water into the carb with engine running, usually dissolves any carbon build up. if that doesn't work, start buying diesel at the gas station... can't beat em- join em. :cheers:
Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
Re: run on (emsrescu)
Running a cooler plug cold also help if all other adj are right on (timing, idle speed, throttle positon, etc.) There is a thread on plugs that has a link to the AC delco site with info on telling how to decode the plugs numbers.
EDIT here is the link:
www.acdelco.com/html/pi_plugs_ident.htm
[Modified by Fevre, 10:41 AM 7/16/2003]
EDIT here is the link:
www.acdelco.com/html/pi_plugs_ident.htm
[Modified by Fevre, 10:41 AM 7/16/2003]
Safety Car
Joined: Jun 2001
Posts: 4,004
Likes: 2
From: Severna Park Md
Re: run on (emsrescu)
Run on is usually caused by carbon build up or too high of temp in combustion chamber. High combustion chamber temps can be caused by reterded ignition or retarded cam timing(worn timing chain), too high of heat range plugs, lean fuel mixture. what happens is after you shut off the ignition, something in the chamber, either casting bumps or carbon bits are still glowing red hot and providing an ignition source allowing the engine to run on. Start by changing to a colder plug, setting the ignition to specs, and making sure the engine is not overheating. I had a high mileage olds 350 once that would always run a bit hot and on. Eventually the timing chain went south and the car wouldnt start. after I put a new timing chain on it cool down and didnt run on any more.
