BBD to weber conversion problem
 

I have an 89YJ automatic, previous owner replaced the engine with an
overbored 4.2 out of an 85 which runs great. He removed the cat, pulse air.
The CTO with those 5 vac nipples was not connected at all. We had the
charcoal cannister break, purge cap broke off and replaced it from one out
of an XJ [unknown year], still had problems so I rebuilt the BBD, ran
better but still would not idle and stalls when slowing down for lights and
stop signs. Tough in traffic...
At any rate I put one of the weber 551 kits in today and it runs, about the
same as it ran with the BBD. I also replace the two rubber grommets for the
PCV in the front and vent in the back. The vent is connected to the K&N
filter. I also bought all new vac lines from the parts store and started
replacing the to no avail.
Some questions, what is "manifold" vacum and what is "ported" vacum. Am I
fighting the computer here. Those two valves on the firewall, green one is
supposed be manifold vac and the tan one is supposed to be ported vac, are
not connected though one was with the BBD and was connected to the base of
the carb under the old choke.
Will replacing the CTO gain me anything ??
Do I need to do the nutterbypass on this. We don't have emissions testing
here but I still plan on putting the cat back in and I would like the O2
sensor to work but not at the cost of putting the bbd back in.
I tried hooking the vac lines up in various configurations due to my lack
of understanding the manifold and ported vacs. The weber has two vac
hookups, one in the front that I plugged the PCV into and the other on the
side under the electric choke. Are either of them ported vacum ?
This vacum stuff is driving me nuts, all I want it to do is run....

Re: BBD to weber conversion problem
 

Hoo boy, where to start?

Ok, forget the O2 sensor, it will have zero effect on anything without
the stock carb on there.

Then get the computer dead! It has gone into 'limp home' mode and has
clamped down on the timing. I find it easiest to just add two new wires
when doing the 'Nutter' bypass. I hook the orange and purple wires at
the distributor directly to the orange and purple wires at the ignition
module.

You then can forget all about 99% of the vacuum lines. None of the
vacuum switches or any other emissions part will be in the loop. That
includes the sol vac unit that was on the BBD to step up the idle when
the tranny is put in drive. You just have to up the curb idle a bit to
make up for it.

An XJ canister???????

I don't think that will work at all and could be half your headaches.
Does it 'look' the same as the one you took out? If it has the same
purge valve on it, then it might function ok, but the XJ ones I have
seen didn't have that purge valve on top. (the purge valve is the part
with the small vacuum line going to it)

A manifold vacuum is a nipple that sucks when the engine is idling. A
ported vacuum is a nipple that only sucks when the throttle is opened.

The CTO valve controls vacuum. It has two ports on it that only allow
vacuum to pass between them when the engine is hot. This is needed for
proper EGR and charcoal canister operation.

Both the EGR and the canister purge valves are 'turned on' using a
ported vacuum source routed through the CTO valve. They then only
function when hot and at speed.

The PCV valve goes to a large manifold vacuum nipple. Just before it
goes into the manifold, it needs a T fitting to pick up the charcoal
canister purge line.

Then you need to tag the timing advance to vacuum. Your mileage may
vary, but I get the best performance with the timing advance hooked into
the same 'ported' vacuum line that goes to the CTO and controls the EGR
valve. You T it in before the CTO or just where it comes out of the
carb.

Here are a couple links that explain it fairly well:

http://home.sprynet.com/~dale02/ignmods.htm

http://home.sprynet.com/~dale02/list.htm

All I have working on mine is a large manifold vacuum nipple for the PCV
and canister purge lines, a small manifold vacuum line for the air
filter flaps to avoid iced carbs and a ported vacuum line for my timing
advance and to feed the CTO which turns on my EGR valve and canister
purge valve to allow the canister to purge into the PCV system.

Hope some of this helps,

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Rich Pierson wrote:
>
> I have an 89YJ automatic, previous owner replaced the engine with an
> overbored 4.2 out of an 85 which runs great. He removed the cat, pulse air.
> The CTO with those 5 vac nipples was not connected at all. We had the
> charcoal cannister break, purge cap broke off and replaced it from one out
> of an XJ [unknown year], still had problems so I rebuilt the BBD, ran
> better but still would not idle and stalls when slowing down for lights and
> stop signs. Tough in traffic...
> At any rate I put one of the weber 551 kits in today and it runs, about the
> same as it ran with the BBD. I also replace the two rubber grommets for the
> PCV in the front and vent in the back. The vent is connected to the K&N
> filter. I also bought all new vac lines from the parts store and started
> replacing the to no avail.
> Some questions, what is "manifold" vacum and what is "ported" vacum. Am I
> fighting the computer here. Those two valves on the firewall, green one is
> supposed be manifold vac and the tan one is supposed to be ported vac, are
> not connected though one was with the BBD and was connected to the base of
> the carb under the old choke.
> Will replacing the CTO gain me anything ??
> Do I need to do the nutterbypass on this. We don't have emissions testing
> here but I still plan on putting the cat back in and I would like the O2
> sensor to work but not at the cost of putting the bbd back in.
> I tried hooking the vac lines up in various configurations due to my lack
> of understanding the manifold and ported vacs. The weber has two vac
> hookups, one in the front that I plugged the PCV into and the other on the
> side under the electric choke. Are either of them ported vacum ?
> This vacum stuff is driving me nuts, all I want it to do is run....

Re: BBD to weber conversion problem
 

Hoo boy, where to start?

Ok, forget the O2 sensor, it will have zero effect on anything without
the stock carb on there.

Then get the computer dead! It has gone into 'limp home' mode and has
clamped down on the timing. I find it easiest to just add two new wires
when doing the 'Nutter' bypass. I hook the orange and purple wires at
the distributor directly to the orange and purple wires at the ignition
module.

You then can forget all about 99% of the vacuum lines. None of the
vacuum switches or any other emissions part will be in the loop. That
includes the sol vac unit that was on the BBD to step up the idle when
the tranny is put in drive. You just have to up the curb idle a bit to
make up for it.

An XJ canister???????

I don't think that will work at all and could be half your headaches.
Does it 'look' the same as the one you took out? If it has the same
purge valve on it, then it might function ok, but the XJ ones I have
seen didn't have that purge valve on top. (the purge valve is the part
with the small vacuum line going to it)

A manifold vacuum is a nipple that sucks when the engine is idling. A
ported vacuum is a nipple that only sucks when the throttle is opened.

The CTO valve controls vacuum. It has two ports on it that only allow
vacuum to pass between them when the engine is hot. This is needed for
proper EGR and charcoal canister operation.

Both the EGR and the canister purge valves are 'turned on' using a
ported vacuum source routed through the CTO valve. They then only
function when hot and at speed.

The PCV valve goes to a large manifold vacuum nipple. Just before it
goes into the manifold, it needs a T fitting to pick up the charcoal
canister purge line.

Then you need to tag the timing advance to vacuum. Your mileage may
vary, but I get the best performance with the timing advance hooked into
the same 'ported' vacuum line that goes to the CTO and controls the EGR
valve. You T it in before the CTO or just where it comes out of the
carb.

Here are a couple links that explain it fairly well:

http://home.sprynet.com/~dale02/ignmods.htm

http://home.sprynet.com/~dale02/list.htm

All I have working on mine is a large manifold vacuum nipple for the PCV
and canister purge lines, a small manifold vacuum line for the air
filter flaps to avoid iced carbs and a ported vacuum line for my timing
advance and to feed the CTO which turns on my EGR valve and canister
purge valve to allow the canister to purge into the PCV system.

Hope some of this helps,

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Rich Pierson wrote:
>
> I have an 89YJ automatic, previous owner replaced the engine with an
> overbored 4.2 out of an 85 which runs great. He removed the cat, pulse air.
> The CTO with those 5 vac nipples was not connected at all. We had the
> charcoal cannister break, purge cap broke off and replaced it from one out
> of an XJ [unknown year], still had problems so I rebuilt the BBD, ran
> better but still would not idle and stalls when slowing down for lights and
> stop signs. Tough in traffic...
> At any rate I put one of the weber 551 kits in today and it runs, about the
> same as it ran with the BBD. I also replace the two rubber grommets for the
> PCV in the front and vent in the back. The vent is connected to the K&N
> filter. I also bought all new vac lines from the parts store and started
> replacing the to no avail.
> Some questions, what is "manifold" vacum and what is "ported" vacum. Am I
> fighting the computer here. Those two valves on the firewall, green one is
> supposed be manifold vac and the tan one is supposed to be ported vac, are
> not connected though one was with the BBD and was connected to the base of
> the carb under the old choke.
> Will replacing the CTO gain me anything ??
> Do I need to do the nutterbypass on this. We don't have emissions testing
> here but I still plan on putting the cat back in and I would like the O2
> sensor to work but not at the cost of putting the bbd back in.
> I tried hooking the vac lines up in various configurations due to my lack
> of understanding the manifold and ported vacs. The weber has two vac
> hookups, one in the front that I plugged the PCV into and the other on the
> side under the electric choke. Are either of them ported vacum ?
> This vacum stuff is driving me nuts, all I want it to do is run....

Re: BBD to weber conversion problem
 

Thank Mike,
OK, did the bypass and it fired right up and after about 2 min the idle
seemed to calm down at 500rpm which is the fastest we could adjust the
webers idle control screw into. It did not stall when going into drive or
reverse so maybe we are almost there. Still idles a bit rough but I think
my vac is still hosed up wrong. I pulled the charcoal cannister out and
cleaned the filter [somehow I doubt AZ carries them in stock]. Son is
putting on a new steering stablizer so right now so I'm in here with more
questions and staying out of his way.
The cannister has the exact same markings on it as the one in the link
picture. So I am 'assuming' that it should work.

I can take out the two vacs on the fire wall, done.
How can I eliminate that CTO ?? Do I want to, not really sure it even
works, looks original.
I was thinking of picking up a vacumn tree.
The way I see it all I need is vac advance for the distributor and that
should be ported, yes.

PCV into the base of the weber
Purge signal from ported vacumn
Purge line from manifold vacumn
Line from cannister to gas tank
Vent line from the carb bowl to the cannister


The vac resevoir is also not connected, does that get manifold or ported
vacumn.
We're getting there :-)
I was a bit ticked as I could not find my amphenol tool to take the
connector on the ignition control module apart. Got all the connectors in
my amphenol kit but do you think I could find the $#%($ tool.

The weber has one vac stem on the side, near the valve cover, is that
considered 'ported' or unported ??
Mike Romain <romainm@sympatico.ca> wrote in
news:3F5B4118.41A45472@sympatico.ca:

> Hoo boy, where to start?
>
> Ok, forget the O2 sensor, it will have zero effect on anything without
> the stock carb on there.
>
> Then get the computer dead! It has gone into 'limp home' mode and has
> clamped down on the timing. I find it easiest to just add two new
> wires when doing the 'Nutter' bypass. I hook the orange and purple
> wires at the distributor directly to the orange and purple wires at
> the ignition module.
>
> You then can forget all about 99% of the vacuum lines. None of the
> vacuum switches or any other emissions part will be in the loop. That
> includes the sol vac unit that was on the BBD to step up the idle when
> the tranny is put in drive. You just have to up the curb idle a bit
> to make up for it.
>
> An XJ canister???????
>
> I don't think that will work at all and could be half your headaches.
> Does it 'look' the same as the one you took out? If it has the same
> purge valve on it, then it might function ok, but the XJ ones I have
> seen didn't have that purge valve on top. (the purge valve is the
> part with the small vacuum line going to it)
>
> A manifold vacuum is a nipple that sucks when the engine is idling. A
> ported vacuum is a nipple that only sucks when the throttle is opened.
>
> The CTO valve controls vacuum. It has two ports on it that only allow
> vacuum to pass between them when the engine is hot. This is needed
> for proper EGR and charcoal canister operation.
>
> Both the EGR and the canister purge valves are 'turned on' using a
> ported vacuum source routed through the CTO valve. They then only
> function when hot and at speed.
>
> The PCV valve goes to a large manifold vacuum nipple. Just before it
> goes into the manifold, it needs a T fitting to pick up the charcoal
> canister purge line.
>
> Then you need to tag the timing advance to vacuum. Your mileage may
> vary, but I get the best performance with the timing advance hooked
> into the same 'ported' vacuum line that goes to the CTO and controls
> the EGR valve. You T it in before the CTO or just where it comes out
> of the carb.
>
> Here are a couple links that explain it fairly well:
>
> http://home.sprynet.com/~dale02/ignmods.htm
>
> http://home.sprynet.com/~dale02/list.htm
>
> All I have working on mine is a large manifold vacuum nipple for the
> PCV and canister purge lines, a small manifold vacuum line for the air
> filter flaps to avoid iced carbs and a ported vacuum line for my
> timing advance and to feed the CTO which turns on my EGR valve and
> canister purge valve to allow the canister to purge into the PCV
> system.
>
> Hope some of this helps,
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> Rich Pierson wrote:
>>
>> I have an 89YJ automatic, previous owner replaced the engine with an
>> overbored 4.2 out of an 85 which runs great. He removed the cat,
>> pulse air. The CTO with those 5 vac nipples was not connected at all.
>> We had the charcoal cannister break, purge cap broke off and replaced
>> it from one out of an XJ [unknown year], still had problems so I
>> rebuilt the BBD, ran better but still would not idle and stalls when
>> slowing down for lights and stop signs. Tough in traffic...
>> At any rate I put one of the weber 551 kits in today and it runs,
>> about the same as it ran with the BBD. I also replace the two rubber
>> grommets for the PCV in the front and vent in the back. The vent is
>> connected to the K&N filter. I also bought all new vac lines from the
>> parts store and started replacing the to no avail.
>> Some questions, what is "manifold" vacum and what is "ported" vacum.
>> Am I fighting the computer here. Those two valves on the firewall,
>> green one is supposed be manifold vac and the tan one is supposed to
>> be ported vac, are not connected though one was with the BBD and was
>> connected to the base of the carb under the old choke.
>> Will replacing the CTO gain me anything ??
>> Do I need to do the nutterbypass on this. We don't have emissions
>> testing here but I still plan on putting the cat back in and I would
>> like the O2 sensor to work but not at the cost of putting the bbd
>> back in. I tried hooking the vac lines up in various configurations
>> due to my lack of understanding the manifold and ported vacs. The
>> weber has two vac hookups, one in the front that I plugged the PCV
>> into and the other on the side under the electric choke. Are either
>> of them ported vacum ? This vacum stuff is driving me nuts, all I
>> want it to do is run....

Re: BBD to weber conversion problem
 

Thank Mike,
OK, did the bypass and it fired right up and after about 2 min the idle
seemed to calm down at 500rpm which is the fastest we could adjust the
webers idle control screw into. It did not stall when going into drive or
reverse so maybe we are almost there. Still idles a bit rough but I think
my vac is still hosed up wrong. I pulled the charcoal cannister out and
cleaned the filter [somehow I doubt AZ carries them in stock]. Son is
putting on a new steering stablizer so right now so I'm in here with more
questions and staying out of his way.
The cannister has the exact same markings on it as the one in the link
picture. So I am 'assuming' that it should work.

I can take out the two vacs on the fire wall, done.
How can I eliminate that CTO ?? Do I want to, not really sure it even
works, looks original.
I was thinking of picking up a vacumn tree.
The way I see it all I need is vac advance for the distributor and that
should be ported, yes.

PCV into the base of the weber
Purge signal from ported vacumn
Purge line from manifold vacumn
Line from cannister to gas tank
Vent line from the carb bowl to the cannister


The vac resevoir is also not connected, does that get manifold or ported
vacumn.
We're getting there :-)
I was a bit ticked as I could not find my amphenol tool to take the
connector on the ignition control module apart. Got all the connectors in
my amphenol kit but do you think I could find the $#%($ tool.

The weber has one vac stem on the side, near the valve cover, is that
considered 'ported' or unported ??
Mike Romain <romainm@sympatico.ca> wrote in
news:3F5B4118.41A45472@sympatico.ca:

> Hoo boy, where to start?
>
> Ok, forget the O2 sensor, it will have zero effect on anything without
> the stock carb on there.
>
> Then get the computer dead! It has gone into 'limp home' mode and has
> clamped down on the timing. I find it easiest to just add two new
> wires when doing the 'Nutter' bypass. I hook the orange and purple
> wires at the distributor directly to the orange and purple wires at
> the ignition module.
>
> You then can forget all about 99% of the vacuum lines. None of the
> vacuum switches or any other emissions part will be in the loop. That
> includes the sol vac unit that was on the BBD to step up the idle when
> the tranny is put in drive. You just have to up the curb idle a bit
> to make up for it.
>
> An XJ canister???????
>
> I don't think that will work at all and could be half your headaches.
> Does it 'look' the same as the one you took out? If it has the same
> purge valve on it, then it might function ok, but the XJ ones I have
> seen didn't have that purge valve on top. (the purge valve is the
> part with the small vacuum line going to it)
>
> A manifold vacuum is a nipple that sucks when the engine is idling. A
> ported vacuum is a nipple that only sucks when the throttle is opened.
>
> The CTO valve controls vacuum. It has two ports on it that only allow
> vacuum to pass between them when the engine is hot. This is needed
> for proper EGR and charcoal canister operation.
>
> Both the EGR and the canister purge valves are 'turned on' using a
> ported vacuum source routed through the CTO valve. They then only
> function when hot and at speed.
>
> The PCV valve goes to a large manifold vacuum nipple. Just before it
> goes into the manifold, it needs a T fitting to pick up the charcoal
> canister purge line.
>
> Then you need to tag the timing advance to vacuum. Your mileage may
> vary, but I get the best performance with the timing advance hooked
> into the same 'ported' vacuum line that goes to the CTO and controls
> the EGR valve. You T it in before the CTO or just where it comes out
> of the carb.
>
> Here are a couple links that explain it fairly well:
>
> http://home.sprynet.com/~dale02/ignmods.htm
>
> http://home.sprynet.com/~dale02/list.htm
>
> All I have working on mine is a large manifold vacuum nipple for the
> PCV and canister purge lines, a small manifold vacuum line for the air
> filter flaps to avoid iced carbs and a ported vacuum line for my
> timing advance and to feed the CTO which turns on my EGR valve and
> canister purge valve to allow the canister to purge into the PCV
> system.
>
> Hope some of this helps,
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> Rich Pierson wrote:
>>
>> I have an 89YJ automatic, previous owner replaced the engine with an
>> overbored 4.2 out of an 85 which runs great. He removed the cat,
>> pulse air. The CTO with those 5 vac nipples was not connected at all.
>> We had the charcoal cannister break, purge cap broke off and replaced
>> it from one out of an XJ [unknown year], still had problems so I
>> rebuilt the BBD, ran better but still would not idle and stalls when
>> slowing down for lights and stop signs. Tough in traffic...
>> At any rate I put one of the weber 551 kits in today and it runs,
>> about the same as it ran with the BBD. I also replace the two rubber
>> grommets for the PCV in the front and vent in the back. The vent is
>> connected to the K&N filter. I also bought all new vac lines from the
>> parts store and started replacing the to no avail.
>> Some questions, what is "manifold" vacum and what is "ported" vacum.
>> Am I fighting the computer here. Those two valves on the firewall,
>> green one is supposed be manifold vac and the tan one is supposed to
>> be ported vac, are not connected though one was with the BBD and was
>> connected to the base of the carb under the old choke.
>> Will replacing the CTO gain me anything ??
>> Do I need to do the nutterbypass on this. We don't have emissions
>> testing here but I still plan on putting the cat back in and I would
>> like the O2 sensor to work but not at the cost of putting the bbd
>> back in. I tried hooking the vac lines up in various configurations
>> due to my lack of understanding the manifold and ported vacs. The
>> weber has two vac hookups, one in the front that I plugged the PCV
>> into and the other on the side under the electric choke. Are either
>> of them ported vacum ? This vacum stuff is driving me nuts, all I
>> want it to do is run....