backfire

[douglas king]

my truck just started backfiring out of the muffler when i shut off my truck, it runs good with no backfiring while driving but when it backfires right after shuting down it is not very loud but i would like to fix it before it does.

[Don S]

..
douglas king...
... Back-firing and dieseling or after-run can be caused by some of the following.. Fuel – air mix could be to rich or lean. Idle adjustments may set to rich.. The timing may be set with to much advance. A lot of carburetors are equipped with anti dieseling solenoids and it could be out of adjustment or disconnected.
… Sticking valves would also be a good guess. Carbon can form on the intake side of valves and stem causing them to not operate smoothly and ‘leak’ fire from normal ignition. Some of these conditions cause 'backfiring' in the intake system.
… Carbon is also a big promoter of dieseling back-firing and pinging (pre-ignition) and a poor running engine.
Here’s a link to the gentle and successful way I have been keeping carbon out of my FSJ for 18 years

link> UPPER-LUBES CAN MAKE YOUR FSJ ENGINE RUN BETTER & REDUCE CARBON (http://groups.msn.com/ATexasOklahomaJeepClub/ouraycotopic.msnw?action=get_message&mview=0&ID_Message=595&LastModified=4675409674755661827)

If the ignition is turned off something has to be glowing hot enough to ignite the fuel that is dumped the last few turns of the engine.

Good Luck.. http://www.boylover.net/ubb/graemlins/cool_shades.gifand CUL.. Don S..