Re: YJ runs rough on startup?
 

Micah wrote:
> On Mar 2, 6:20 pm, "L.W. \(Bill\) ------ III" <billhug...@cox.net>
> wrote:
>> Why???????
>> God Bless America, Bill 0|||||||0
>> mailto:LW------...@aol.comhttp://www.----------.com/
>>
>> "Micah" <mgoodenb...@gmail.com> wrote in message
>>
>> news:1172812833.002733.117390@j27g2000cwj.googlegr oups.com...
>>
>>> Hello everyone. 258, Manual, 1988. Last weekend I swapped out my
>>> Weber K551 for my newly rebuilt Carter.
>>> <snip>
>> --
>> Posted via a free Usenet account fromhttp://www.teranews.com
>
> Bill, I just don't know how to answer that.
>
> Mike, it's been 70-80 degrees here in Texas the past couple of weeks
> and low humidity. And it ran fine after starting cold with the Weber
> on it a week ago.
>
> I did check on the choke pull-off earlier today, it doesn't seem to be
> functioning correctly (though I can't figure out what could possibly
> be causing it to malfunction). I started my engine today, let it
> rumble for a few seconds and stall, then I wedged the choke plate open
> about 1/4 inch, started it, and it ran perfectly at fast idle. Then,
> around 120 degrees I pulled the wedge out of the choke and it settled
> down to its curb idle. Seems to run fine if I manually do the job of
> my choke pull-off. The vacuum hose on it is brand new. Anything I
> can do or test?
>

When the engine first starts, there is a choke pull off valve that pulls
open the choke just slightly so it doesn't chug out.

This valve is on the choke side of the carb and is hooked to direct
manifold vacuum via the nipple that is dead center and the bottom back
of the carb.

To test this, you can unplug the line to the carb base and suck on the
line. The pull off is supposed to hold vacuum.

When this pull off is working right, it should open the choke between
0.130 and 0.140 inches open as soon as the engine turns on. The setting
calls for the choke to be turned rich 'while it is being set', that is
just to make sure there isn't any slop in the main choke linkage which
would allow the choke to open too much.

This choke pull off is powerful. It will pull my manual choke cable
handle in as it fires up. I can feel the cable move.

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)

Re: YJ runs rough on startup?
 

Micah wrote:
> On Mar 2, 6:20 pm, "L.W. \(Bill\) ------ III" <billhug...@cox.net>
> wrote:
>> Why???????
>> God Bless America, Bill 0|||||||0
>> mailto:LW------...@aol.comhttp://www.----------.com/
>>
>> "Micah" <mgoodenb...@gmail.com> wrote in message
>>
>> news:1172812833.002733.117390@j27g2000cwj.googlegr oups.com...
>>
>>> Hello everyone. 258, Manual, 1988. Last weekend I swapped out my
>>> Weber K551 for my newly rebuilt Carter.
>>> <snip>
>> --
>> Posted via a free Usenet account fromhttp://www.teranews.com
>
> Bill, I just don't know how to answer that.
>
> Mike, it's been 70-80 degrees here in Texas the past couple of weeks
> and low humidity. And it ran fine after starting cold with the Weber
> on it a week ago.
>
> I did check on the choke pull-off earlier today, it doesn't seem to be
> functioning correctly (though I can't figure out what could possibly
> be causing it to malfunction). I started my engine today, let it
> rumble for a few seconds and stall, then I wedged the choke plate open
> about 1/4 inch, started it, and it ran perfectly at fast idle. Then,
> around 120 degrees I pulled the wedge out of the choke and it settled
> down to its curb idle. Seems to run fine if I manually do the job of
> my choke pull-off. The vacuum hose on it is brand new. Anything I
> can do or test?
>

When the engine first starts, there is a choke pull off valve that pulls
open the choke just slightly so it doesn't chug out.

This valve is on the choke side of the carb and is hooked to direct
manifold vacuum via the nipple that is dead center and the bottom back
of the carb.

To test this, you can unplug the line to the carb base and suck on the
line. The pull off is supposed to hold vacuum.

When this pull off is working right, it should open the choke between
0.130 and 0.140 inches open as soon as the engine turns on. The setting
calls for the choke to be turned rich 'while it is being set', that is
just to make sure there isn't any slop in the main choke linkage which
would allow the choke to open too much.

This choke pull off is powerful. It will pull my manual choke cable
handle in as it fires up. I can feel the cable move.

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)

Re: YJ runs rough on startup?
 

Mike Romain wrote:

> When the engine first starts, there is a choke pull off valve that
> pulls open the choke just slightly so it doesn't chug out.
>
> This valve is on the choke side of the carb and is hooked to direct
> manifold vacuum via the nipple that is dead center and the bottom back
> of the carb.

Which reminds me. If your carb isn't sitting flat or the gasket it torn,
you will never get enough vac to pull in that choke. A bit of carb cleaner
sprayed around the base will let you know if there is a leak going on.

--
DougW

Re: YJ runs rough on startup?
 

Mike Romain wrote:

> When the engine first starts, there is a choke pull off valve that
> pulls open the choke just slightly so it doesn't chug out.
>
> This valve is on the choke side of the carb and is hooked to direct
> manifold vacuum via the nipple that is dead center and the bottom back
> of the carb.

Which reminds me. If your carb isn't sitting flat or the gasket it torn,
you will never get enough vac to pull in that choke. A bit of carb cleaner
sprayed around the base will let you know if there is a leak going on.

--
DougW

Re: YJ runs rough on startup?
 

Mike Romain wrote:

> When the engine first starts, there is a choke pull off valve that
> pulls open the choke just slightly so it doesn't chug out.
>
> This valve is on the choke side of the carb and is hooked to direct
> manifold vacuum via the nipple that is dead center and the bottom back
> of the carb.

Which reminds me. If your carb isn't sitting flat or the gasket it torn,
you will never get enough vac to pull in that choke. A bit of carb cleaner
sprayed around the base will let you know if there is a leak going on.

--
DougW

Re: YJ runs rough on startup?
 

I tested it pretty thoroughly yesterday. Sucked on the hose to the
pull-back and it... surprise... pulled back. That section of vacuum
hose is brand new. It seems I'm just not getting any manifold vac on
startup. I checked all the carb-intake bolts, they're all at the 16
foot pounds recommended by my Haynes manual. Both base gaskets are
new (above and below the spacer). I also sprayed carb cleaner around
the base like Doug recommended and didn't find any leaks. Perhaps I
have another leak elsewhere? Just can't figure this one out.

On the bright side, when I start it, then immediately prop the choke
plate open it runs fine. I then have to wait for the choke to open
enough on its own before I can pull my wedge (a bottle cap-ha), put
the air filter lid back on, and drive away.

I'm considering installing a remote control wire (I have a few spares
laying in a box somewhere) so I can pull the choke back on my own
after the engine starts. Not entirely desirable as a long-term
solution, but it could hold me until I track down the source of the
problem/leak.

Thanks for your help, everyone. Any more suggestions, and I'd be glad
to hear them...

Re: YJ runs rough on startup?
 

I tested it pretty thoroughly yesterday. Sucked on the hose to the
pull-back and it... surprise... pulled back. That section of vacuum
hose is brand new. It seems I'm just not getting any manifold vac on
startup. I checked all the carb-intake bolts, they're all at the 16
foot pounds recommended by my Haynes manual. Both base gaskets are
new (above and below the spacer). I also sprayed carb cleaner around
the base like Doug recommended and didn't find any leaks. Perhaps I
have another leak elsewhere? Just can't figure this one out.

On the bright side, when I start it, then immediately prop the choke
plate open it runs fine. I then have to wait for the choke to open
enough on its own before I can pull my wedge (a bottle cap-ha), put
the air filter lid back on, and drive away.

I'm considering installing a remote control wire (I have a few spares
laying in a box somewhere) so I can pull the choke back on my own
after the engine starts. Not entirely desirable as a long-term
solution, but it could hold me until I track down the source of the
problem/leak.

Thanks for your help, everyone. Any more suggestions, and I'd be glad
to hear them...

Re: YJ runs rough on startup?
 

I tested it pretty thoroughly yesterday. Sucked on the hose to the
pull-back and it... surprise... pulled back. That section of vacuum
hose is brand new. It seems I'm just not getting any manifold vac on
startup. I checked all the carb-intake bolts, they're all at the 16
foot pounds recommended by my Haynes manual. Both base gaskets are
new (above and below the spacer). I also sprayed carb cleaner around
the base like Doug recommended and didn't find any leaks. Perhaps I
have another leak elsewhere? Just can't figure this one out.

On the bright side, when I start it, then immediately prop the choke
plate open it runs fine. I then have to wait for the choke to open
enough on its own before I can pull my wedge (a bottle cap-ha), put
the air filter lid back on, and drive away.

I'm considering installing a remote control wire (I have a few spares
laying in a box somewhere) so I can pull the choke back on my own
after the engine starts. Not entirely desirable as a long-term
solution, but it could hold me until I track down the source of the
problem/leak.

Thanks for your help, everyone. Any more suggestions, and I'd be glad
to hear them...

Re: YJ runs rough on startup?
 

Micah wrote:
> I tested it pretty thoroughly yesterday. Sucked on the hose to the
> pull-back and it... surprise... pulled back. That section of vacuum
> hose is brand new. It seems I'm just not getting any manifold vac on
> startup. I checked all the carb-intake bolts, they're all at the 16
> foot pounds recommended by my Haynes manual. Both base gaskets are
> new (above and below the spacer). I also sprayed carb cleaner around
> the base like Doug recommended and didn't find any leaks. Perhaps I
> have another leak elsewhere? Just can't figure this one out.

Do you have a vac assisted brake? If so, plug that line off and try
again. Same thing with every other vac line that comes from the
intake rail.

hmm... does you Jeep have a vac reservoir under the battery? IIRC those
used to rot out after a few years.

I use a vac gauge and a small hand-pump to test lines.
http://www.tooldesk.com/products/pro...il.aspx+id+986
Just never go over 20in of vac or you risk causing problems
in the system. (20in is below what a normal engine pulls on
deceleration)


--
DougW

Re: YJ runs rough on startup?
 

Micah wrote:
> I tested it pretty thoroughly yesterday. Sucked on the hose to the
> pull-back and it... surprise... pulled back. That section of vacuum
> hose is brand new. It seems I'm just not getting any manifold vac on
> startup. I checked all the carb-intake bolts, they're all at the 16
> foot pounds recommended by my Haynes manual. Both base gaskets are
> new (above and below the spacer). I also sprayed carb cleaner around
> the base like Doug recommended and didn't find any leaks. Perhaps I
> have another leak elsewhere? Just can't figure this one out.

Do you have a vac assisted brake? If so, plug that line off and try
again. Same thing with every other vac line that comes from the
intake rail.

hmm... does you Jeep have a vac reservoir under the battery? IIRC those
used to rot out after a few years.

I use a vac gauge and a small hand-pump to test lines.
http://www.tooldesk.com/products/pro...il.aspx+id+986
Just never go over 20in of vac or you risk causing problems
in the system. (20in is below what a normal engine pulls on
deceleration)


--
DougW