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.
>
> 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...
>

I would next verify you have vacuum coming out that nipple on the carb.
It would be obvious with your finger.

If there is no vacuum, maybe the carb base plate didn't get in right
side up. It has notches at the edge of the main passages that need to
be up. These provide the channel for the manifold vacuum.

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:
> 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...
>

I would next verify you have vacuum coming out that nipple on the carb.
It would be obvious with your finger.

If there is no vacuum, maybe the carb base plate didn't get in right
side up. It has notches at the edge of the main passages that need to
be up. These provide the channel for the manifold vacuum.

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:
> 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...
>

I would next verify you have vacuum coming out that nipple on the carb.
It would be obvious with your finger.

If there is no vacuum, maybe the carb base plate didn't get in right
side up. It has notches at the edge of the main passages that need to
be up. These provide the channel for the manifold vacuum.

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)