cold start sluggishness
12-10-2006, 01:57 AM
#71
Guest
Posts: n/a
Re: cold start sluggishness
On Sat, 09 Dec 2006 22:07:21 -0800, Outatime <user@example.net> wrote:
>bllsht wrote:
>
>> Since EGR doesn't cause a lean condition, larger jets would do nothing
>> to 'compensate' for it. Exhaust gas is inert. It doesn't change the
>> mixture, it only takes up space to keep peak combustion temperature
>> down.
>
>We will have to agree to disagree on this one. IMO, EGR porting is
>nothing more than a poorly-controlled vacuum leak; increase or decrease
>the flow into the intake manifold below the carburetor venturi and the
>fuel mixture changes. This can be easily demonstrated by disconnecting
>the diaphram vacuum tube, apply enough suction to open the pintle valve
>to introduce lots of inert exhaust gas, and observe the engine die
>immediately from an excessively lean mixture. Smog techs often used
>this method to verify proper EGR valve operation.
If what you're selling is correct, then why use exhaust gas? Why not
just create a vacuum leak? Because lean is not the answer to
preventing NOx formation. In fact, leaning out the mixture will
increase combustion temp and NOx production.
The engine dies when EGR is applied at idle because the cylinder is
filled with inert gas that won't burn. Not because it's lean. That's
the way EGR works. No agreeing to disagree. It is what it is.
>bllsht wrote:
>
>> Since EGR doesn't cause a lean condition, larger jets would do nothing
>> to 'compensate' for it. Exhaust gas is inert. It doesn't change the
>> mixture, it only takes up space to keep peak combustion temperature
>> down.
>
>We will have to agree to disagree on this one. IMO, EGR porting is
>nothing more than a poorly-controlled vacuum leak; increase or decrease
>the flow into the intake manifold below the carburetor venturi and the
>fuel mixture changes. This can be easily demonstrated by disconnecting
>the diaphram vacuum tube, apply enough suction to open the pintle valve
>to introduce lots of inert exhaust gas, and observe the engine die
>immediately from an excessively lean mixture. Smog techs often used
>this method to verify proper EGR valve operation.
If what you're selling is correct, then why use exhaust gas? Why not
just create a vacuum leak? Because lean is not the answer to
preventing NOx formation. In fact, leaning out the mixture will
increase combustion temp and NOx production.
The engine dies when EGR is applied at idle because the cylinder is
filled with inert gas that won't burn. Not because it's lean. That's
the way EGR works. No agreeing to disagree. It is what it is.
12-10-2006, 01:57 AM
#72
Guest
Posts: n/a
Re: cold start sluggishness
On Sat, 09 Dec 2006 22:07:21 -0800, Outatime <user@example.net> wrote:
>bllsht wrote:
>
>> Since EGR doesn't cause a lean condition, larger jets would do nothing
>> to 'compensate' for it. Exhaust gas is inert. It doesn't change the
>> mixture, it only takes up space to keep peak combustion temperature
>> down.
>
>We will have to agree to disagree on this one. IMO, EGR porting is
>nothing more than a poorly-controlled vacuum leak; increase or decrease
>the flow into the intake manifold below the carburetor venturi and the
>fuel mixture changes. This can be easily demonstrated by disconnecting
>the diaphram vacuum tube, apply enough suction to open the pintle valve
>to introduce lots of inert exhaust gas, and observe the engine die
>immediately from an excessively lean mixture. Smog techs often used
>this method to verify proper EGR valve operation.
If what you're selling is correct, then why use exhaust gas? Why not
just create a vacuum leak? Because lean is not the answer to
preventing NOx formation. In fact, leaning out the mixture will
increase combustion temp and NOx production.
The engine dies when EGR is applied at idle because the cylinder is
filled with inert gas that won't burn. Not because it's lean. That's
the way EGR works. No agreeing to disagree. It is what it is.
>bllsht wrote:
>
>> Since EGR doesn't cause a lean condition, larger jets would do nothing
>> to 'compensate' for it. Exhaust gas is inert. It doesn't change the
>> mixture, it only takes up space to keep peak combustion temperature
>> down.
>
>We will have to agree to disagree on this one. IMO, EGR porting is
>nothing more than a poorly-controlled vacuum leak; increase or decrease
>the flow into the intake manifold below the carburetor venturi and the
>fuel mixture changes. This can be easily demonstrated by disconnecting
>the diaphram vacuum tube, apply enough suction to open the pintle valve
>to introduce lots of inert exhaust gas, and observe the engine die
>immediately from an excessively lean mixture. Smog techs often used
>this method to verify proper EGR valve operation.
If what you're selling is correct, then why use exhaust gas? Why not
just create a vacuum leak? Because lean is not the answer to
preventing NOx formation. In fact, leaning out the mixture will
increase combustion temp and NOx production.
The engine dies when EGR is applied at idle because the cylinder is
filled with inert gas that won't burn. Not because it's lean. That's
the way EGR works. No agreeing to disagree. It is what it is.
12-10-2006, 01:57 AM
#73
Guest
Posts: n/a
Re: cold start sluggishness
On Sat, 09 Dec 2006 22:07:21 -0800, Outatime <user@example.net> wrote:
>bllsht wrote:
>
>> Since EGR doesn't cause a lean condition, larger jets would do nothing
>> to 'compensate' for it. Exhaust gas is inert. It doesn't change the
>> mixture, it only takes up space to keep peak combustion temperature
>> down.
>
>We will have to agree to disagree on this one. IMO, EGR porting is
>nothing more than a poorly-controlled vacuum leak; increase or decrease
>the flow into the intake manifold below the carburetor venturi and the
>fuel mixture changes. This can be easily demonstrated by disconnecting
>the diaphram vacuum tube, apply enough suction to open the pintle valve
>to introduce lots of inert exhaust gas, and observe the engine die
>immediately from an excessively lean mixture. Smog techs often used
>this method to verify proper EGR valve operation.
If what you're selling is correct, then why use exhaust gas? Why not
just create a vacuum leak? Because lean is not the answer to
preventing NOx formation. In fact, leaning out the mixture will
increase combustion temp and NOx production.
The engine dies when EGR is applied at idle because the cylinder is
filled with inert gas that won't burn. Not because it's lean. That's
the way EGR works. No agreeing to disagree. It is what it is.
>bllsht wrote:
>
>> Since EGR doesn't cause a lean condition, larger jets would do nothing
>> to 'compensate' for it. Exhaust gas is inert. It doesn't change the
>> mixture, it only takes up space to keep peak combustion temperature
>> down.
>
>We will have to agree to disagree on this one. IMO, EGR porting is
>nothing more than a poorly-controlled vacuum leak; increase or decrease
>the flow into the intake manifold below the carburetor venturi and the
>fuel mixture changes. This can be easily demonstrated by disconnecting
>the diaphram vacuum tube, apply enough suction to open the pintle valve
>to introduce lots of inert exhaust gas, and observe the engine die
>immediately from an excessively lean mixture. Smog techs often used
>this method to verify proper EGR valve operation.
If what you're selling is correct, then why use exhaust gas? Why not
just create a vacuum leak? Because lean is not the answer to
preventing NOx formation. In fact, leaning out the mixture will
increase combustion temp and NOx production.
The engine dies when EGR is applied at idle because the cylinder is
filled with inert gas that won't burn. Not because it's lean. That's
the way EGR works. No agreeing to disagree. It is what it is.
12-10-2006, 04:42 AM
#74
Guest
Posts: n/a
Re: Here's a Goodie! Re: cold start sluggishness - -------DL.jpg (1/1) [85K] - -------DL.jpg (1/1) [85K]
On this day of this month, in a year likely to be unrecorded in human
history, L.W.(Bill) ------ III wrote:
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
Craig was right, /most/ people stop playing this game around 8 years old.
Which is still a year or two beyond Slick Billy's intellectual age.
Man, he really is an internet Peeping Tom.......
--
"Jeeps can get up, and jeeps can also go down. Why can't Bill?"
-- Nancy ------ III
history, L.W.(Bill) ------ III wrote:
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
Craig was right, /most/ people stop playing this game around 8 years old.
Which is still a year or two beyond Slick Billy's intellectual age.
Man, he really is an internet Peeping Tom.......
--
"Jeeps can get up, and jeeps can also go down. Why can't Bill?"
-- Nancy ------ III
12-10-2006, 04:42 AM
#75
Guest
Posts: n/a
Re: Here's a Goodie! Re: cold start sluggishness - -------DL.jpg (1/1) [85K] - -------DL.jpg (1/1) [85K]
On this day of this month, in a year likely to be unrecorded in human
history, L.W.(Bill) ------ III wrote:
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
Craig was right, /most/ people stop playing this game around 8 years old.
Which is still a year or two beyond Slick Billy's intellectual age.
Man, he really is an internet Peeping Tom.......
--
"Jeeps can get up, and jeeps can also go down. Why can't Bill?"
-- Nancy ------ III
history, L.W.(Bill) ------ III wrote:
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
Craig was right, /most/ people stop playing this game around 8 years old.
Which is still a year or two beyond Slick Billy's intellectual age.
Man, he really is an internet Peeping Tom.......
--
"Jeeps can get up, and jeeps can also go down. Why can't Bill?"
-- Nancy ------ III
12-10-2006, 04:42 AM
#76
Guest
Posts: n/a
Re: Here's a Goodie! Re: cold start sluggishness - -------DL.jpg (1/1) [85K] - -------DL.jpg (1/1) [85K]
On this day of this month, in a year likely to be unrecorded in human
history, L.W.(Bill) ------ III wrote:
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
Craig was right, /most/ people stop playing this game around 8 years old.
Which is still a year or two beyond Slick Billy's intellectual age.
Man, he really is an internet Peeping Tom.......
--
"Jeeps can get up, and jeeps can also go down. Why can't Bill?"
-- Nancy ------ III
history, L.W.(Bill) ------ III wrote:
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
> Lets see yours
Craig was right, /most/ people stop playing this game around 8 years old.
Which is still a year or two beyond Slick Billy's intellectual age.
Man, he really is an internet Peeping Tom.......
--
"Jeeps can get up, and jeeps can also go down. Why can't Bill?"
-- Nancy ------ III
12-10-2006, 05:40 AM
#77
Guest
Posts: n/a
Re: Here's a Goodie! Re: cold start sluggishness - -------DL.jpg(1/1) [85K] - -------DL.jpg (1/1) [85K]
There you go again, the jealous, really jealous, I can't believe
how jealous this little draft dodging coward schizophrenic psychopath
liar hiding in Vancouver who's only way to get attention is to make a
fool of it's self. With an obsession the other perverts here. With
extreme jealous ranting over my documents/possessions, committing
forgery over many of them proving I'm an American man. You remind me of
a little rat dog, like a Mexican Chiwawa with it's senseless barking, me
too, me too. And the poor thing, you're too girlie to take
responsibility for yourself again, by signing your statement like a man.
You're not worth any more time when a cut and paste this same
paragraph it fits so well!
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/
how jealous this little draft dodging coward schizophrenic psychopath
liar hiding in Vancouver who's only way to get attention is to make a
fool of it's self. With an obsession the other perverts here. With
extreme jealous ranting over my documents/possessions, committing
forgery over many of them proving I'm an American man. You remind me of
a little rat dog, like a Mexican Chiwawa with it's senseless barking, me
too, me too. And the poor thing, you're too girlie to take
responsibility for yourself again, by signing your statement like a man.
You're not worth any more time when a cut and paste this same
paragraph it fits so well!
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/
12-10-2006, 05:40 AM
#78
Guest
Posts: n/a
Re: Here's a Goodie! Re: cold start sluggishness - -------DL.jpg(1/1) [85K] - -------DL.jpg (1/1) [85K]
There you go again, the jealous, really jealous, I can't believe
how jealous this little draft dodging coward schizophrenic psychopath
liar hiding in Vancouver who's only way to get attention is to make a
fool of it's self. With an obsession the other perverts here. With
extreme jealous ranting over my documents/possessions, committing
forgery over many of them proving I'm an American man. You remind me of
a little rat dog, like a Mexican Chiwawa with it's senseless barking, me
too, me too. And the poor thing, you're too girlie to take
responsibility for yourself again, by signing your statement like a man.
You're not worth any more time when a cut and paste this same
paragraph it fits so well!
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/
how jealous this little draft dodging coward schizophrenic psychopath
liar hiding in Vancouver who's only way to get attention is to make a
fool of it's self. With an obsession the other perverts here. With
extreme jealous ranting over my documents/possessions, committing
forgery over many of them proving I'm an American man. You remind me of
a little rat dog, like a Mexican Chiwawa with it's senseless barking, me
too, me too. And the poor thing, you're too girlie to take
responsibility for yourself again, by signing your statement like a man.
You're not worth any more time when a cut and paste this same
paragraph it fits so well!
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/
12-10-2006, 05:40 AM
#79
Guest
Posts: n/a
Re: Here's a Goodie! Re: cold start sluggishness - -------DL.jpg(1/1) [85K] - -------DL.jpg (1/1) [85K]
There you go again, the jealous, really jealous, I can't believe
how jealous this little draft dodging coward schizophrenic psychopath
liar hiding in Vancouver who's only way to get attention is to make a
fool of it's self. With an obsession the other perverts here. With
extreme jealous ranting over my documents/possessions, committing
forgery over many of them proving I'm an American man. You remind me of
a little rat dog, like a Mexican Chiwawa with it's senseless barking, me
too, me too. And the poor thing, you're too girlie to take
responsibility for yourself again, by signing your statement like a man.
You're not worth any more time when a cut and paste this same
paragraph it fits so well!
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/
how jealous this little draft dodging coward schizophrenic psychopath
liar hiding in Vancouver who's only way to get attention is to make a
fool of it's self. With an obsession the other perverts here. With
extreme jealous ranting over my documents/possessions, committing
forgery over many of them proving I'm an American man. You remind me of
a little rat dog, like a Mexican Chiwawa with it's senseless barking, me
too, me too. And the poor thing, you're too girlie to take
responsibility for yourself again, by signing your statement like a man.
You're not worth any more time when a cut and paste this same
paragraph it fits so well!
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/
12-10-2006, 09:30 AM
#80
Guest
Posts: n/a
Re: cold start sluggishness
Yeah - that is what I was thinking on the whistle. I will check all
the temp controlled vacuum lines and switches first. They may be two
separate problems that happen to coincide. I guess the reason I
figured my choke wasn't the culprit is that at idle it runs perfectly
throughout the warmup period and the bogging doesn't start happening
until the whistle begins and then goes away when the whistling becomes
quieter again at operating temperature.
Mike Romain wrote:
> I think I would first be looking at the air filter flaps and their
> controls or vacuum lines for a leak. These are active on a cold
> engine. The EGR even has a thermostat inside the air filter.
>
> Second I would be checking the carb's base screws to be sure the carb is
> bolted down tight.
>
> Third I would be looking really close at the choke vacuum pull off
> valve. It is on the back corner of the carb with a vacuum line running
> to it. I would want to make sure it isn't leaking.
>
> You can carefully spray some carb cleaner or WD40 along the carb base
> and along the intake manifold gasket to check for leaks. If the engine
> rumbles when you spray, you have a leak.
>
> Besides the noise, your carb sounds like the typical automatic choke
> issue. The thing is on a bimetal spring timer that doesn't care how
> warm the engine actually is so when the engine is half way warm, the
> choke is open too much so it bogs like mad. You have to feather the gas
> pedal up and down to keep it running under load and 2 foot drive them.
> You 'can' adjust the choke for how rich it runs until it opens by
> loosening the three screws on the cover and turning it. It has indexing
> lines on it. Unless the carb number is 8349 or 8351, it should be 1
> notch rich. Or you can go manual choke easily.
>
> 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)
>
> Deano wrote:
> >
> > I know a few other folks have posted other cold-related issues and
> > received lost of responses, but none seemed to match quite right.
> >
> > 86 cj7 258, carter bbd, nutter bypass
> >
> > I am trying to figure out if there could be a relationship between a
> > very loud whistling (a vacuum leak I haven't found yet) and some
> > serious sluggishness while the engine is cold. It was 15 or 18 degrees
> > this morning (-10C) and it exhibited the typical symptoms. Starts and
> > idles perfectly and in fact runs great for the first 2-3 minutes. Then
> > the whistling starts and with the whistling comes a huge bogging issue
> > under any load at all. I believe the only delayed vacuum line should
> > be the thermal vacuum switch that purges the canister and controls the
> > EGR. I know it is not the EGR as it blocked off. Anyone else hearing
> > something familiar or following the train of thought here? Could a
> > vacuum leak cause a serious bogging issue until warm and then go away?.
> >
> > Would love to hear any thoughts or ideas on this.
> >
> > Thanks
the temp controlled vacuum lines and switches first. They may be two
separate problems that happen to coincide. I guess the reason I
figured my choke wasn't the culprit is that at idle it runs perfectly
throughout the warmup period and the bogging doesn't start happening
until the whistle begins and then goes away when the whistling becomes
quieter again at operating temperature.
Mike Romain wrote:
> I think I would first be looking at the air filter flaps and their
> controls or vacuum lines for a leak. These are active on a cold
> engine. The EGR even has a thermostat inside the air filter.
>
> Second I would be checking the carb's base screws to be sure the carb is
> bolted down tight.
>
> Third I would be looking really close at the choke vacuum pull off
> valve. It is on the back corner of the carb with a vacuum line running
> to it. I would want to make sure it isn't leaking.
>
> You can carefully spray some carb cleaner or WD40 along the carb base
> and along the intake manifold gasket to check for leaks. If the engine
> rumbles when you spray, you have a leak.
>
> Besides the noise, your carb sounds like the typical automatic choke
> issue. The thing is on a bimetal spring timer that doesn't care how
> warm the engine actually is so when the engine is half way warm, the
> choke is open too much so it bogs like mad. You have to feather the gas
> pedal up and down to keep it running under load and 2 foot drive them.
> You 'can' adjust the choke for how rich it runs until it opens by
> loosening the three screws on the cover and turning it. It has indexing
> lines on it. Unless the carb number is 8349 or 8351, it should be 1
> notch rich. Or you can go manual choke easily.
>
> 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)
>
> Deano wrote:
> >
> > I know a few other folks have posted other cold-related issues and
> > received lost of responses, but none seemed to match quite right.
> >
> > 86 cj7 258, carter bbd, nutter bypass
> >
> > I am trying to figure out if there could be a relationship between a
> > very loud whistling (a vacuum leak I haven't found yet) and some
> > serious sluggishness while the engine is cold. It was 15 or 18 degrees
> > this morning (-10C) and it exhibited the typical symptoms. Starts and
> > idles perfectly and in fact runs great for the first 2-3 minutes. Then
> > the whistling starts and with the whistling comes a huge bogging issue
> > under any load at all. I believe the only delayed vacuum line should
> > be the thermal vacuum switch that purges the canister and controls the
> > EGR. I know it is not the EGR as it blocked off. Anyone else hearing
> > something familiar or following the train of thought here? Could a
> > vacuum leak cause a serious bogging issue until warm and then go away?.
> >
> > Would love to hear any thoughts or ideas on this.
> >
> > Thanks