"Dieseling" as yours sounds like it is doing is often caused by a
build-up of carbon inside the combustion chambers. The carbon
continues
to glow after the last combustion stroke which propels the engine in
another rotation again, which with a mechanical fuel pump keeps the
fuel
going. Then the glowing carbon re-ignites the fuel mixture in place
of
the spark plug again.

The cure, if this is the problem and it sounds like it is, is to get
rid
of the carbon build-up. The easiest way to do this is to slowly (!!)
feed 12-16 ounces of plain water into the air intake as the engine is
running, keeping the RPMs up slightly. NO, this will NOT cause
hydrolock providing you feed the water in slowly and in a controlled
manner over a minute to two minutes. Just slowly trickle it and
maintain control over the water so you don't dump it in too quickly by

accident.

The water will scavenge the carbon deposits and though it may take
more
than one treatment, this will leave the combustion chambers clean as a

whistle. No I didn't just make this up, this technique has been used
at
least from the thirties or forties to get rid of carbon. The water
creates mini shock-waves that act to break the carbon up so it can be
ejected through the exhaust system.

Try it.

Jerry

Jay wrote:
> I just bought this Jeep a few weeks ago and it was running just
fine.
> About a week after I got it, I realized it needed a new carb as the
> float was stuck in the current one. I replaced the carb with a
rebuilt
> one and it was running just fine again. Now, maybe two weeks later,
> all of a sudden when I turn the ignition off when I get home, the
> engine shuts off then maybe a fraction of a second later it starts
> shaking like it wants to start up again (sort of like bucking?). I
> have noticed the shaking is directly related to the amount of time I
> have been driving for. If I run out for a few minutes, it might not
> shake at all when I turn it off. But if I go for a half hour long
> drive, when I go to turn it off, the engine starts shaking. Any
ideas
> what could be going on? Any help at all would be greatly
appreciated!
> I have a 1986 CJ7 73K, 5 speed manual with an inline 6. Thanks,
Jason
>
>
--
Jerry Bransford
PP-ASEL N6TAY
See the Geezer Jeep at
http://members.***.net/jerrypb/


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It is not just the carbon but a combo of engine temp and fuel octane
too. Cars since later 70's and 87 octane gas have anti dieseling
solenoids that close throttle plates completely at key off to prevent
this. (when key is on it opens plates to idle position) Rather than
possibly damaging your motor with advise below, I would suggest that
you check operation of the anti dieseling solenoid and repair or
replace if need be. A slower idle speed can help too. Also if it is a
automatic and it is throwing a big fit on shut down just shut it off
in gear while you load it up a bit (you do not have to firewall it!)
on brakes and it will stop the instant you switch off the key.

On Wed, 06 Jun 2007 17:02:36 -0500,
jerrypb@***-dot-net.no-spam.invalid (Jerry Bransford) wrote:

>"Dieseling" as yours sounds like it is doing is often caused by a
>build-up of carbon inside the combustion chambers. The carbon
>continues
>to glow after the last combustion stroke which propels the engine in
>another rotation again, which with a mechanical fuel pump keeps the
>fuel
>going. Then the glowing carbon re-ignites the fuel mixture in place
>of
>the spark plug again.
>
>The cure, if this is the problem and it sounds like it is, is to get
>rid
>of the carbon build-up. The easiest way to do this is to slowly (!!)
>feed 12-16 ounces of plain water into the air intake as the engine is
>running, keeping the RPMs up slightly. NO, this will NOT cause
>hydrolock providing you feed the water in slowly and in a controlled
>manner over a minute to two minutes. Just slowly trickle it and
>maintain control over the water so you don't dump it in too quickly by
>
>accident.
>
>The water will scavenge the carbon deposits and though it may take
>more
>than one treatment, this will leave the combustion chambers clean as a
>
>whistle. No I didn't just make this up, this technique has been used
>at
>least from the thirties or forties to get rid of carbon. The water
>creates mini shock-waves that act to break the carbon up so it can be
>ejected through the exhaust system.
>
>Try it.
>
>Jerry
>
>Jay wrote:
>> I just bought this Jeep a few weeks ago and it was running just
>fine.
>> About a week after I got it, I realized it needed a new carb as the
>> float was stuck in the current one. I replaced the carb with a
>rebuilt
>> one and it was running just fine again. Now, maybe two weeks later,
>> all of a sudden when I turn the ignition off when I get home, the
>> engine shuts off then maybe a fraction of a second later it starts
>> shaking like it wants to start up again (sort of like bucking?). I
>> have noticed the shaking is directly related to the amount of time I
>> have been driving for. If I run out for a few minutes, it might not
>> shake at all when I turn it off. But if I go for a half hour long
>> drive, when I go to turn it off, the engine starts shaking. Any
>ideas
>> what could be going on? Any help at all would be greatly
>appreciated!
>> I have a 1986 CJ7 73K, 5 speed manual with an inline 6. Thanks,
>Jason
>>
>>
-----------------
TheSnoMan.com

 

It is not just the carbon but a combo of engine temp and fuel octane
too. Cars since later 70's and 87 octane gas have anti dieseling
solenoids that close throttle plates completely at key off to prevent
this. (when key is on it opens plates to idle position) Rather than
possibly damaging your motor with advise below, I would suggest that
you check operation of the anti dieseling solenoid and repair or
replace if need be. A slower idle speed can help too. Also if it is a
automatic and it is throwing a big fit on shut down just shut it off
in gear while you load it up a bit (you do not have to firewall it!)
on brakes and it will stop the instant you switch off the key.

On Wed, 06 Jun 2007 17:02:36 -0500,
jerrypb@***-dot-net.no-spam.invalid (Jerry Bransford) wrote:

>"Dieseling" as yours sounds like it is doing is often caused by a
>build-up of carbon inside the combustion chambers. The carbon
>continues
>to glow after the last combustion stroke which propels the engine in
>another rotation again, which with a mechanical fuel pump keeps the
>fuel
>going. Then the glowing carbon re-ignites the fuel mixture in place
>of
>the spark plug again.
>
>The cure, if this is the problem and it sounds like it is, is to get
>rid
>of the carbon build-up. The easiest way to do this is to slowly (!!)
>feed 12-16 ounces of plain water into the air intake as the engine is
>running, keeping the RPMs up slightly. NO, this will NOT cause
>hydrolock providing you feed the water in slowly and in a controlled
>manner over a minute to two minutes. Just slowly trickle it and
>maintain control over the water so you don't dump it in too quickly by
>
>accident.
>
>The water will scavenge the carbon deposits and though it may take
>more
>than one treatment, this will leave the combustion chambers clean as a
>
>whistle. No I didn't just make this up, this technique has been used
>at
>least from the thirties or forties to get rid of carbon. The water
>creates mini shock-waves that act to break the carbon up so it can be
>ejected through the exhaust system.
>
>Try it.
>
>Jerry
>
>Jay wrote:
>> I just bought this Jeep a few weeks ago and it was running just
>fine.
>> About a week after I got it, I realized it needed a new carb as the
>> float was stuck in the current one. I replaced the carb with a
>rebuilt
>> one and it was running just fine again. Now, maybe two weeks later,
>> all of a sudden when I turn the ignition off when I get home, the
>> engine shuts off then maybe a fraction of a second later it starts
>> shaking like it wants to start up again (sort of like bucking?). I
>> have noticed the shaking is directly related to the amount of time I
>> have been driving for. If I run out for a few minutes, it might not
>> shake at all when I turn it off. But if I go for a half hour long
>> drive, when I go to turn it off, the engine starts shaking. Any
>ideas
>> what could be going on? Any help at all would be greatly
>appreciated!
>> I have a 1986 CJ7 73K, 5 speed manual with an inline 6. Thanks,
>Jason
>>
>>
-----------------
TheSnoMan.com

 

It is not just the carbon but a combo of engine temp and fuel octane
too. Cars since later 70's and 87 octane gas have anti dieseling
solenoids that close throttle plates completely at key off to prevent
this. (when key is on it opens plates to idle position) Rather than
possibly damaging your motor with advise below, I would suggest that
you check operation of the anti dieseling solenoid and repair or
replace if need be. A slower idle speed can help too. Also if it is a
automatic and it is throwing a big fit on shut down just shut it off
in gear while you load it up a bit (you do not have to firewall it!)
on brakes and it will stop the instant you switch off the key.

On Wed, 06 Jun 2007 17:02:36 -0500,
jerrypb@***-dot-net.no-spam.invalid (Jerry Bransford) wrote:

>"Dieseling" as yours sounds like it is doing is often caused by a
>build-up of carbon inside the combustion chambers. The carbon
>continues
>to glow after the last combustion stroke which propels the engine in
>another rotation again, which with a mechanical fuel pump keeps the
>fuel
>going. Then the glowing carbon re-ignites the fuel mixture in place
>of
>the spark plug again.
>
>The cure, if this is the problem and it sounds like it is, is to get
>rid
>of the carbon build-up. The easiest way to do this is to slowly (!!)
>feed 12-16 ounces of plain water into the air intake as the engine is
>running, keeping the RPMs up slightly. NO, this will NOT cause
>hydrolock providing you feed the water in slowly and in a controlled
>manner over a minute to two minutes. Just slowly trickle it and
>maintain control over the water so you don't dump it in too quickly by
>
>accident.
>
>The water will scavenge the carbon deposits and though it may take
>more
>than one treatment, this will leave the combustion chambers clean as a
>
>whistle. No I didn't just make this up, this technique has been used
>at
>least from the thirties or forties to get rid of carbon. The water
>creates mini shock-waves that act to break the carbon up so it can be
>ejected through the exhaust system.
>
>Try it.
>
>Jerry
>
>Jay wrote:
>> I just bought this Jeep a few weeks ago and it was running just
>fine.
>> About a week after I got it, I realized it needed a new carb as the
>> float was stuck in the current one. I replaced the carb with a
>rebuilt
>> one and it was running just fine again. Now, maybe two weeks later,
>> all of a sudden when I turn the ignition off when I get home, the
>> engine shuts off then maybe a fraction of a second later it starts
>> shaking like it wants to start up again (sort of like bucking?). I
>> have noticed the shaking is directly related to the amount of time I
>> have been driving for. If I run out for a few minutes, it might not
>> shake at all when I turn it off. But if I go for a half hour long
>> drive, when I go to turn it off, the engine starts shaking. Any
>ideas
>> what could be going on? Any help at all would be greatly
>appreciated!
>> I have a 1986 CJ7 73K, 5 speed manual with an inline 6. Thanks,
>Jason
>>
>>
-----------------
TheSnoMan.com

 

It is not just the carbon but a combo of engine temp and fuel octane
too. Cars since later 70's and 87 octane gas have anti dieseling
solenoids that close throttle plates completely at key off to prevent
this. (when key is on it opens plates to idle position) Rather than
possibly damaging your motor with advise below, I would suggest that
you check operation of the anti dieseling solenoid and repair or
replace if need be. A slower idle speed can help too. Also if it is a
automatic and it is throwing a big fit on shut down just shut it off
in gear while you load it up a bit (you do not have to firewall it!)
on brakes and it will stop the instant you switch off the key.

On Wed, 06 Jun 2007 17:02:36 -0500,
jerrypb@***-dot-net.no-spam.invalid (Jerry Bransford) wrote:

>"Dieseling" as yours sounds like it is doing is often caused by a
>build-up of carbon inside the combustion chambers. The carbon
>continues
>to glow after the last combustion stroke which propels the engine in
>another rotation again, which with a mechanical fuel pump keeps the
>fuel
>going. Then the glowing carbon re-ignites the fuel mixture in place
>of
>the spark plug again.
>
>The cure, if this is the problem and it sounds like it is, is to get
>rid
>of the carbon build-up. The easiest way to do this is to slowly (!!)
>feed 12-16 ounces of plain water into the air intake as the engine is
>running, keeping the RPMs up slightly. NO, this will NOT cause
>hydrolock providing you feed the water in slowly and in a controlled
>manner over a minute to two minutes. Just slowly trickle it and
>maintain control over the water so you don't dump it in too quickly by
>
>accident.
>
>The water will scavenge the carbon deposits and though it may take
>more
>than one treatment, this will leave the combustion chambers clean as a
>
>whistle. No I didn't just make this up, this technique has been used
>at
>least from the thirties or forties to get rid of carbon. The water
>creates mini shock-waves that act to break the carbon up so it can be
>ejected through the exhaust system.
>
>Try it.
>
>Jerry
>
>Jay wrote:
>> I just bought this Jeep a few weeks ago and it was running just
>fine.
>> About a week after I got it, I realized it needed a new carb as the
>> float was stuck in the current one. I replaced the carb with a
>rebuilt
>> one and it was running just fine again. Now, maybe two weeks later,
>> all of a sudden when I turn the ignition off when I get home, the
>> engine shuts off then maybe a fraction of a second later it starts
>> shaking like it wants to start up again (sort of like bucking?). I
>> have noticed the shaking is directly related to the amount of time I
>> have been driving for. If I run out for a few minutes, it might not
>> shake at all when I turn it off. But if I go for a half hour long
>> drive, when I go to turn it off, the engine starts shaking. Any
>ideas
>> what could be going on? Any help at all would be greatly
>appreciated!
>> I have a 1986 CJ7 73K, 5 speed manual with an inline 6. Thanks,
>Jason
>>
>>
-----------------
TheSnoMan.com