dieseling...
Thread Starter
|
Junior User
Joined: May 2007
Posts: 75
Likes: 0
From: SO CAL
dieseling...
ok so i run my truck for a while, and when i turn the key off, it almost dies but fires a couple more times then it turns off. i think this is called dieseling, am i right?? and iam almost sure it is carburetion. anything i can do to stop this or help it?? it just all of a sudden started happening. i have a holley 600cfm if that matters.
thanks
-brian
thanks
-brian
Thread Starter
|
Junior User
Joined: May 2007
Posts: 75
Likes: 0
From: SO CAL
um well actually i just rebuilt the carb yeastarday. everything is replaced and cleaned very well. but, it very well might be bad gas. thats a good thought. i will definantly take a look into that, it only has a little under a 1/4 tank.....
thanks for the help.
-brian
thanks for the help.
-brian
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
Dieseling is caused by too high of a curb idle. This is common after you rebuild a carb. You need to bring your idle down. If your carb employs an idle-stop solenoid, you need to be using it. If not, just bring your idle down a bit.
If that doesn't solve it, some less common causes include too far advanced timing, a vacuum leak, overly lean idle mixture, or too low octane fuel. But my money is on your idle being too high (almost always is the problem). Dieseling occurs when you still have a way for enough air (and hence fuel) to get in the intake (caused by throttle plates open too far at idle), and the heat of the engine provides an ignition source. It worsens as an engine ages and cylinder walls and piston surfaces develop carbon "hot spots" that act like glow plugs in a diesel, and hence the name "dieseling."
If that doesn't solve it, some less common causes include too far advanced timing, a vacuum leak, overly lean idle mixture, or too low octane fuel. But my money is on your idle being too high (almost always is the problem). Dieseling occurs when you still have a way for enough air (and hence fuel) to get in the intake (caused by throttle plates open too far at idle), and the heat of the engine provides an ignition source. It worsens as an engine ages and cylinder walls and piston surfaces develop carbon "hot spots" that act like glow plugs in a diesel, and hence the name "dieseling."
Last edited by fmc400; Jun 14, 2007 at 11:30 PM.
