Dieseling!

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May 6, 2005 | 11:10 AM

savage066

Thread Starter

Mountain Pass

Joined: Dec 2004

Posts: 123

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From: Maryland

Dieseling!

anybody know how to stop run-on effectively? i have a remanufacured YF-1A on my 300 and no matter what i do, it diesels after i shut the engine off. Timing is stock at 6 degrees BTDC, i set it recently. i'm not sure if the mixture is too rich...the exhaust doesn't smell like it is. either way, if i lean it out, it starts running rougher. is this just an old 1-barrel issue or is there a carb problem?

May 6, 2005 | 02:49 PM

Boss50

Elder User

Joined: Feb 2003

Posts: 871

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From: Coleman, Wisconsin

Theres something on the carb that is suppose to keep it from doing that. I just leave my truck in Drive when I shut it off and it doesn't diesel.

May 6, 2005 | 03:06 PM

n9lhm

Senior User

Joined: Apr 2005

Posts: 446

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From: South Bend, IN

Dieseling is usually an idle speed issue -- how fast is it idling? What year is it, did it have a throttle stop solenoid on it to begin with? Brian

May 6, 2005 | 03:08 PM

daveee

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Joined: Mar 2002

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I have somewhat the same problem on my 78 F-150 4x4 when I have it checked for Arizona emissions. In order to pass, I must lean it out 1/2 turn and increase the throttle adjustment 1/2 turn. It then diesels when I turn it off. In order to prevent the dieseling I must richen it up and turn down the throttle, but then I flunk emmissions. Timing is at 6 BTDC also. I would appreciate any ideas for a permenite solution

May 6, 2005 | 06:51 PM

tetraruby300

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Joined: Oct 2003

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From: Central Coast, CA

Incorrect timing can also cause dieseling.

May 6, 2005 | 08:11 PM

daveee

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Joined: Mar 2002

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The spec is 6 degrees BTDC. That is my point. It is not incorrect timing.

May 6, 2005 | 10:58 PM

oldhalftons

Postmaster

Joined: Feb 2003

Posts: 3,439

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From: Spokane WA

run it at 10-12 BTDC and back off the idle screw to lower the RPM back to where it was before it was increased by advancing the timing.
It will stop dieseling.

Last edited by oldhalftons; May 6, 2005 at 11:01 PM.