a.limberg@insightbb.com wrote:
> On Feb 23, 8:12 am, "Highcountry" <highcountry2...@hotmail.com> wrote:
>> My vote is for the "stepper motor" enrichment system also! When
>> built, they were worried about NOX emissions caused by lean
>> mixtures. That stepper dumps fuel into the carb when the Oxygen
>> Sensor detects lean mixture. On a 25 year old vehicle with 100 feet
>> of vacuum lines that operate everything, you may never find it.
>>
>> A thread tap and a couple of set screws blocking the enrichment system
>> permanently cured mine while keeping everything under the hood looking
>> "correct". I had 30 years experience with the Carter BBD and they
>> always ran flawlessly, so I knew there was a "monkey in the works"
>> somewhere. Sure enough, good old Uncle EPA forced Carter to ruin
>> their design by adding that stepper . After the "retro"
>> modification, my jeep now runs absolutely perfect. Instant starts
>> hot or cold, 20 mph in high gear and you can floor the accelerator and
>> get a smooth speed up. And running 65 to 75 on the Interstate, it
>> gets 15 to 16 MPG. I just did a 200 mile round trip yesterday (with
>> the top off-Yeah!) so that is verified mileage.
>>
>> Another good modification that is also reversable if you ever need to
>> is the "Nutter Bypass", it completely "retros" your ignition to the
>> reliably simple 70's version.
>>
>> http://www.4x4wire.com/jeep/tech/ele...jn-ignition99/
>>
>> Be sure to take a look at the diagrams shown on the above webpage.
>>
>> Good luck, Bruce
>
> This sounds like a solution. I will take advantage of it this weekend.
> It has to be better than the performance that I'm getting now. Thanks
> for your advice, Andy
>

Here is another link on that mod:
http://home.sprynet.com/~dale02/ignmods.htm

I have a couple comments about it. I always just run 2 new wires to
connect the orange and purple wires at the ignition module to the
distributor rather than mess around inside the harness.

I disagree with John Nutter's carb setup. He states to put the stepper
motor's 'air mix' pins into the full rich position or all the way into
the carb. This basically doesn't work for high speed, it only works for
idle and low speeds.

I have found that setting the pins in the center of their travel where
the O2 would have them gets the top speed mix right. This means rocking
them with a small screwdriver until the shoulder of the pin is just
clear of the back wall or removing the stepper and moving them by hand
then putting it back on.

The idle mix is controlled by two screws down front.

You will love the power boost! A good 25% 'seat of the pants boost with
at 'least' a 10 mph per gear increase. My 86 will top out at 4400 rpm
now. 4th gear will bury the speedo and I have no urge to find out how
fast 5th will go...

I can also pass Canadian emissions with the BBD manually tuned. Not
just mine but a lot of friend's rigs too.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

 

a.limberg@insightbb.com wrote:
> On Feb 23, 8:12 am, "Highcountry" <highcountry2...@hotmail.com> wrote:
>> My vote is for the "stepper motor" enrichment system also! When
>> built, they were worried about NOX emissions caused by lean
>> mixtures. That stepper dumps fuel into the carb when the Oxygen
>> Sensor detects lean mixture. On a 25 year old vehicle with 100 feet
>> of vacuum lines that operate everything, you may never find it.
>>
>> A thread tap and a couple of set screws blocking the enrichment system
>> permanently cured mine while keeping everything under the hood looking
>> "correct". I had 30 years experience with the Carter BBD and they
>> always ran flawlessly, so I knew there was a "monkey in the works"
>> somewhere. Sure enough, good old Uncle EPA forced Carter to ruin
>> their design by adding that stepper . After the "retro"
>> modification, my jeep now runs absolutely perfect. Instant starts
>> hot or cold, 20 mph in high gear and you can floor the accelerator and
>> get a smooth speed up. And running 65 to 75 on the Interstate, it
>> gets 15 to 16 MPG. I just did a 200 mile round trip yesterday (with
>> the top off-Yeah!) so that is verified mileage.
>>
>> Another good modification that is also reversable if you ever need to
>> is the "Nutter Bypass", it completely "retros" your ignition to the
>> reliably simple 70's version.
>>
>> http://www.4x4wire.com/jeep/tech/ele...jn-ignition99/
>>
>> Be sure to take a look at the diagrams shown on the above webpage.
>>
>> Good luck, Bruce
>
> This sounds like a solution. I will take advantage of it this weekend.
> It has to be better than the performance that I'm getting now. Thanks
> for your advice, Andy
>

Here is another link on that mod:
http://home.sprynet.com/~dale02/ignmods.htm

I have a couple comments about it. I always just run 2 new wires to
connect the orange and purple wires at the ignition module to the
distributor rather than mess around inside the harness.

I disagree with John Nutter's carb setup. He states to put the stepper
motor's 'air mix' pins into the full rich position or all the way into
the carb. This basically doesn't work for high speed, it only works for
idle and low speeds.

I have found that setting the pins in the center of their travel where
the O2 would have them gets the top speed mix right. This means rocking
them with a small screwdriver until the shoulder of the pin is just
clear of the back wall or removing the stepper and moving them by hand
then putting it back on.

The idle mix is controlled by two screws down front.

You will love the power boost! A good 25% 'seat of the pants boost with
at 'least' a 10 mph per gear increase. My 86 will top out at 4400 rpm
now. 4th gear will bury the speedo and I have no urge to find out how
fast 5th will go...

I can also pass Canadian emissions with the BBD manually tuned. Not
just mine but a lot of friend's rigs too.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

 

Mike is absolutely correct on not messing with the OEM wiring
harness. I elected to splice in two new wires on the distributor
side of the connector and take them to the Ignition Control Box and
splice again on the Box side of those connectors. I would suggest
you make those connections with SOLDER then seal them very well with
some sort of insulation. Also, If you are ever interested in "un-
doing" your work, a replacement control box and distributor module are
all it takes.

Also, I totally removed the "stepper motor metering rod" and blocked
off those fuel passages and reinstalled the stepper motor housing to
maintain appearances. After that, I retuned the BBD to correct the
mixture. The Main Jet metering rods have enough adjustment to give
you MORE than enough fuel. I started out with them at the richest
setting and kept re-adjusting toward lean until I could detect the
beginnings of a "surge" under a load, then went back a tiny bit richer
which left it "spot on". Did the same thing with the accelerator
pump, the factory specification of 1/2' below the carb top boss is too
much of a squirt. With that setting, each time I floored the
accelerator I would get a little puff of black smoke which indicated
"too rich". I lowered the pump rod to about 5/8" below the boss and
black puff went away!

Experimentation is what it is all about. I am sure if I had a
different transmissioin or tire size or differential gears that some
of the settings would require minor tweaks. But to me that is a
major part of the reason for owning a REAL Jeep instead of an
imitation!

Good Luck, Bruce

 

Mike is absolutely correct on not messing with the OEM wiring
harness. I elected to splice in two new wires on the distributor
side of the connector and take them to the Ignition Control Box and
splice again on the Box side of those connectors. I would suggest
you make those connections with SOLDER then seal them very well with
some sort of insulation. Also, If you are ever interested in "un-
doing" your work, a replacement control box and distributor module are
all it takes.

Also, I totally removed the "stepper motor metering rod" and blocked
off those fuel passages and reinstalled the stepper motor housing to
maintain appearances. After that, I retuned the BBD to correct the
mixture. The Main Jet metering rods have enough adjustment to give
you MORE than enough fuel. I started out with them at the richest
setting and kept re-adjusting toward lean until I could detect the
beginnings of a "surge" under a load, then went back a tiny bit richer
which left it "spot on". Did the same thing with the accelerator
pump, the factory specification of 1/2' below the carb top boss is too
much of a squirt. With that setting, each time I floored the
accelerator I would get a little puff of black smoke which indicated
"too rich". I lowered the pump rod to about 5/8" below the boss and
black puff went away!

Experimentation is what it is all about. I am sure if I had a
different transmissioin or tire size or differential gears that some
of the settings would require minor tweaks. But to me that is a
major part of the reason for owning a REAL Jeep instead of an
imitation!

Good Luck, Bruce

 

Mike is absolutely correct on not messing with the OEM wiring
harness. I elected to splice in two new wires on the distributor
side of the connector and take them to the Ignition Control Box and
splice again on the Box side of those connectors. I would suggest
you make those connections with SOLDER then seal them very well with
some sort of insulation. Also, If you are ever interested in "un-
doing" your work, a replacement control box and distributor module are
all it takes.

Also, I totally removed the "stepper motor metering rod" and blocked
off those fuel passages and reinstalled the stepper motor housing to
maintain appearances. After that, I retuned the BBD to correct the
mixture. The Main Jet metering rods have enough adjustment to give
you MORE than enough fuel. I started out with them at the richest
setting and kept re-adjusting toward lean until I could detect the
beginnings of a "surge" under a load, then went back a tiny bit richer
which left it "spot on". Did the same thing with the accelerator
pump, the factory specification of 1/2' below the carb top boss is too
much of a squirt. With that setting, each time I floored the
accelerator I would get a little puff of black smoke which indicated
"too rich". I lowered the pump rod to about 5/8" below the boss and
black puff went away!

Experimentation is what it is all about. I am sure if I had a
different transmissioin or tire size or differential gears that some
of the settings would require minor tweaks. But to me that is a
major part of the reason for owning a REAL Jeep instead of an
imitation!

Good Luck, Bruce

 

Highcountry wrote:
> Mike is absolutely correct on not messing with the OEM wiring
> harness. I elected to splice in two new wires on the distributor
> side of the connector and take them to the Ignition Control Box and
> splice again on the Box side of those connectors. I would suggest
> you make those connections with SOLDER then seal them very well with
> some sort of insulation. Also, If you are ever interested in "un-
> doing" your work, a replacement control box and distributor module are
> all it takes.
>
> Also, I totally removed the "stepper motor metering rod" and blocked
> off those fuel passages and reinstalled the stepper motor housing to
> maintain appearances. After that, I retuned the BBD to correct the
> mixture. The Main Jet metering rods have enough adjustment to give
> you MORE than enough fuel. I started out with them at the richest
> setting and kept re-adjusting toward lean until I could detect the
> beginnings of a "surge" under a load, then went back a tiny bit richer
> which left it "spot on". Did the same thing with the accelerator
> pump, the factory specification of 1/2' below the carb top boss is too
> much of a squirt. With that setting, each time I floored the
> accelerator I would get a little puff of black smoke which indicated
> "too rich". I lowered the pump rod to about 5/8" below the boss and
> black puff went away!
>
> Experimentation is what it is all about. I am sure if I had a
> different transmissioin or tire size or differential gears that some
> of the settings would require minor tweaks. But to me that is a
> major part of the reason for owning a REAL Jeep instead of an
> imitation!
>
> Good Luck, Bruce
>

Interesting....

Those pins are 'air' mix pins. I have been worried about running mine
too lean and burning up pistons because I run on the highway lots.

I now think I might play a little more with them to see what kind of
mileage I can coax out of her. Originally I had them set to give me 23+
mpg. Now I think they are one notch richer than that because I seem to
be just under 20 mpg or I need to tweak the vacuum piston (main jets)
setting.

There are two main jets inside the carb for high speed. These are
adjustable for the top end mix I think. I tried running with them a bit
rich also just to see if I could burn that alcohol mix crap, but all I
did was drop the mileage even more, no performance increase. Are these
the ones you are 'playing' with?

I would almost think a tailpipe sniffer would be in order to get the
main jets 'proper'. or lots of tweaking.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

 

Highcountry wrote:
> Mike is absolutely correct on not messing with the OEM wiring
> harness. I elected to splice in two new wires on the distributor
> side of the connector and take them to the Ignition Control Box and
> splice again on the Box side of those connectors. I would suggest
> you make those connections with SOLDER then seal them very well with
> some sort of insulation. Also, If you are ever interested in "un-
> doing" your work, a replacement control box and distributor module are
> all it takes.
>
> Also, I totally removed the "stepper motor metering rod" and blocked
> off those fuel passages and reinstalled the stepper motor housing to
> maintain appearances. After that, I retuned the BBD to correct the
> mixture. The Main Jet metering rods have enough adjustment to give
> you MORE than enough fuel. I started out with them at the richest
> setting and kept re-adjusting toward lean until I could detect the
> beginnings of a "surge" under a load, then went back a tiny bit richer
> which left it "spot on". Did the same thing with the accelerator
> pump, the factory specification of 1/2' below the carb top boss is too
> much of a squirt. With that setting, each time I floored the
> accelerator I would get a little puff of black smoke which indicated
> "too rich". I lowered the pump rod to about 5/8" below the boss and
> black puff went away!
>
> Experimentation is what it is all about. I am sure if I had a
> different transmissioin or tire size or differential gears that some
> of the settings would require minor tweaks. But to me that is a
> major part of the reason for owning a REAL Jeep instead of an
> imitation!
>
> Good Luck, Bruce
>

Interesting....

Those pins are 'air' mix pins. I have been worried about running mine
too lean and burning up pistons because I run on the highway lots.

I now think I might play a little more with them to see what kind of
mileage I can coax out of her. Originally I had them set to give me 23+
mpg. Now I think they are one notch richer than that because I seem to
be just under 20 mpg or I need to tweak the vacuum piston (main jets)
setting.

There are two main jets inside the carb for high speed. These are
adjustable for the top end mix I think. I tried running with them a bit
rich also just to see if I could burn that alcohol mix crap, but all I
did was drop the mileage even more, no performance increase. Are these
the ones you are 'playing' with?

I would almost think a tailpipe sniffer would be in order to get the
main jets 'proper'. or lots of tweaking.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

 

Highcountry wrote:
> Mike is absolutely correct on not messing with the OEM wiring
> harness. I elected to splice in two new wires on the distributor
> side of the connector and take them to the Ignition Control Box and
> splice again on the Box side of those connectors. I would suggest
> you make those connections with SOLDER then seal them very well with
> some sort of insulation. Also, If you are ever interested in "un-
> doing" your work, a replacement control box and distributor module are
> all it takes.
>
> Also, I totally removed the "stepper motor metering rod" and blocked
> off those fuel passages and reinstalled the stepper motor housing to
> maintain appearances. After that, I retuned the BBD to correct the
> mixture. The Main Jet metering rods have enough adjustment to give
> you MORE than enough fuel. I started out with them at the richest
> setting and kept re-adjusting toward lean until I could detect the
> beginnings of a "surge" under a load, then went back a tiny bit richer
> which left it "spot on". Did the same thing with the accelerator
> pump, the factory specification of 1/2' below the carb top boss is too
> much of a squirt. With that setting, each time I floored the
> accelerator I would get a little puff of black smoke which indicated
> "too rich". I lowered the pump rod to about 5/8" below the boss and
> black puff went away!
>
> Experimentation is what it is all about. I am sure if I had a
> different transmissioin or tire size or differential gears that some
> of the settings would require minor tweaks. But to me that is a
> major part of the reason for owning a REAL Jeep instead of an
> imitation!
>
> Good Luck, Bruce
>

Interesting....

Those pins are 'air' mix pins. I have been worried about running mine
too lean and burning up pistons because I run on the highway lots.

I now think I might play a little more with them to see what kind of
mileage I can coax out of her. Originally I had them set to give me 23+
mpg. Now I think they are one notch richer than that because I seem to
be just under 20 mpg or I need to tweak the vacuum piston (main jets)
setting.

There are two main jets inside the carb for high speed. These are
adjustable for the top end mix I think. I tried running with them a bit
rich also just to see if I could burn that alcohol mix crap, but all I
did was drop the mileage even more, no performance increase. Are these
the ones you are 'playing' with?

I would almost think a tailpipe sniffer would be in order to get the
main jets 'proper'. or lots of tweaking.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

 

Yup, the "Main Metering Rods" and the "Main Jets" that those rods
operate inside of are your real choice for mixture adjustments.
Being an "old geezer" that grew up tinkering with 60's and 70's
Mopars, I have the advantage of knowing what a BBD is supposed to do
BEFORE "uncle sammies EPA" screwed things up.

The original BBDs did not have that stepper adjustment, and the
passage that it opens and closes did not exist. Knowing that, I
simply blocked them and returned my BBD to a late 1960's state of
tune. I wish I could take you for a ride in my CJ, it amazes
people! You can NOT "bump" the engine over with the starter because
it starts instantly. It idles so smoothly, the only way you can tell
it is running is listening. And I reverified this yesterday, you can
run 20mph in high gear on flat ground and floor the accelerator
resulting in a smooth speed up without any hesitation. I am not
relating all of this to brag, just to convince folks that you CAN get
the BBD to run just fine if you have the skills and time.

To comment on your "tailpipe sniffer" idea, you already have part of
it! Your exhaust pipe has an Oxygen Sensor port, and the performance
industry sells a "mixture monitoring" system that will screw right in
place of the stock O-Sensor. This allows you to observe the mixture
while driving. Hot rodders use them to get the best air to fuel
ratio, so can you!

Hang in there!

 

Yup, the "Main Metering Rods" and the "Main Jets" that those rods
operate inside of are your real choice for mixture adjustments.
Being an "old geezer" that grew up tinkering with 60's and 70's
Mopars, I have the advantage of knowing what a BBD is supposed to do
BEFORE "uncle sammies EPA" screwed things up.

The original BBDs did not have that stepper adjustment, and the
passage that it opens and closes did not exist. Knowing that, I
simply blocked them and returned my BBD to a late 1960's state of
tune. I wish I could take you for a ride in my CJ, it amazes
people! You can NOT "bump" the engine over with the starter because
it starts instantly. It idles so smoothly, the only way you can tell
it is running is listening. And I reverified this yesterday, you can
run 20mph in high gear on flat ground and floor the accelerator
resulting in a smooth speed up without any hesitation. I am not
relating all of this to brag, just to convince folks that you CAN get
the BBD to run just fine if you have the skills and time.

To comment on your "tailpipe sniffer" idea, you already have part of
it! Your exhaust pipe has an Oxygen Sensor port, and the performance
industry sells a "mixture monitoring" system that will screw right in
place of the stock O-Sensor. This allows you to observe the mixture
while driving. Hot rodders use them to get the best air to fuel
ratio, so can you!

Hang in there!