90 YJ carby 4.2 - JeepForum.com
 4Likes
  • 2 Post By Chrisnvegas
  • 1 Post By timatoe
  • 1 Post By Wabatuckian
 
LinkBack Thread Tools
post #1 of 13 Old 05-29-2020, 04:23 PM Thread Starter
ronbros
Registered User
 
Join Date: May 2020
Posts: 7
90 YJ carby 4.2

engine stalls when slowing for a stop, other than that runs fine!


ronbros is offline  
Sponsored Links
Advertisement
 
post #2 of 13 Old 05-29-2020, 04:25 PM
Chrisnvegas
Web Wheeler
 
Chrisnvegas's Avatar
1992 YJ Wrangler 
 
Join Date: Dec 2012
Location: Nevada Territory
Posts: 9,066
Are we to guess which carb you have?

Okay.

I guess you have a Carter and the idle tubes need a cleaning.

"Alferd Packer: “Stand up, you voracious, man-eating son of a *****, stand up! There was seven democrats in Hinsdale County and you up and ate five of them."
Chrisnvegas is offline  
post #3 of 13 Old 05-29-2020, 04:38 PM Thread Starter
ronbros
Registered User
 
Join Date: May 2020
Posts: 7
its an exchange rebuilt carb, the shop that did work could not get it to idle below 2000revs,! (it was on cold fast idle cam so i took it off fast idle and use the idle speed screw) it came to me that way, after much adjustments and trying to get down to 850/900 rpm it starts and runs great , it drives great ,
but when slowing below 10 mph it stalls , and pump the gas couple times fires up instantly!
ronbros is offline  
 
post #4 of 13 Old 05-29-2020, 05:01 PM
jbolty
Moderator
 
jbolty's Avatar
1990 YJ Wrangler 
 
Join Date: Jun 2007
Location: San Diego
Posts: 20,264
Garage
https://www.jeeptech.com/engine/carter.html

.
"The right to be heard does not necessarily include the right to be taken seriously." —Hubert Humphrey
.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
jbolty is offline  
post #5 of 13 Old 05-29-2020, 07:19 PM Thread Starter
ronbros
Registered User
 
Join Date: May 2020
Posts: 7
thanks for the info, i will be doing that mod tommorw!
ron
ronbros is offline  
post #6 of 13 Old 05-29-2020, 07:20 PM Thread Starter
ronbros
Registered User
 
Join Date: May 2020
Posts: 7
thanks for info
ron
ronbros is offline  
post #7 of 13 Old 05-29-2020, 07:22 PM
Chrisnvegas
Web Wheeler
 
Chrisnvegas's Avatar
1992 YJ Wrangler 
 
Join Date: Dec 2012
Location: Nevada Territory
Posts: 9,066
Check for vacuum leaks too.

I like using an unlit propane torch. It's safe and not messy. Safe as long as you aren't smoking while doing it.
Wabatuckian and ronbros like this.

"Alferd Packer: “Stand up, you voracious, man-eating son of a *****, stand up! There was seven democrats in Hinsdale County and you up and ate five of them."
Chrisnvegas is offline  
post #8 of 13 Old 05-30-2020, 10:05 AM Thread Starter
ronbros
Registered User
 
Join Date: May 2020
Posts: 7
well the plot thickens!
air cleaner off , BRIGHT flashlight ,choke wide open(held with small vise grips), and started the ***** up, two pumps of throttle, starts instantly, idle around 850/900 rpm, look down two screw jets , NO fuel drips from venturis and nice and clean(rebuilt carb), give slight rev ,accellpumps look only fair,not a good stright shot of fuel!, NO fuel drips!
small wire measures 35 thou. slide down holes in jets(maybe already done at rebuld)?

OK that done , take her for slow drive, all is good, till i slow for a stop using light brake pressure idle gets rough, BUT push brake quickly and STALLS instantly, couple pumps restarts, rolling slowly and make a turn stall instantly no braking applied? HMM ?
damn the stupid engineers who figured the emissions for the era 70s/ 80s, fresh out of drug infested college(yeah LSD makes engineers smart),, the rats nest of hoses and valves is completely useless!

Last edited by ronbros; 05-30-2020 at 11:09 AM.
ronbros is offline  
post #9 of 13 Old 05-30-2020, 11:07 AM Thread Starter
ronbros
Registered User
 
Join Date: May 2020
Posts: 7
back again ,just say i treat this like an old 1950s basic engine , fuel , spark and it should run ok!
if i take all the non essential hose and valves off , what would i be looking at,Texas has no emission tests on vehicles over 25 yrs, collector car status!
also when i unplug the electric plug on carb nothing happens , runs fine!
i never really liked those electronic carbs!
ron
ronbros is offline  
post #10 of 13 Old 05-30-2020, 11:25 AM
timatoe
Registered User
 
timatoe's Avatar
1990 YJ Wrangler 
 
Join Date: Aug 2006
Location: Grass Valley
Posts: 17,743
If you're getting rid of stuff, google "Nutter Bypass" can't really just start unplugging stuff. I'd check for vacuum leaks around the brake booster too if you're stalling when hitting the brakes.
Wabatuckian likes this.

Quote:
Originally Posted by George Orwell
We sleep safe in our beds because rough men stand ready in the night to visit violence on those who would do us harm.
timatoe is offline  
post #11 of 13 Old 05-30-2020, 03:35 PM
Wabatuckian
Registered User
 
Wabatuckian's Avatar
2004 WJ 
 
Join Date: Aug 2018
Location: Wabash
Posts: 281
Quote:
Originally Posted by ronbros View Post
well the plot thickens!
air cleaner off , BRIGHT flashlight ,choke wide open(held with small vise grips), and started the ***** up, two pumps of throttle, starts instantly, idle around 850/900 rpm, look down two screw jets , NO fuel drips from venturis and nice and clean(rebuilt carb), give slight rev ,accellpumps look only fair,not a good stright shot of fuel!, NO fuel drips!
small wire measures 35 thou. slide down holes in jets(maybe already done at rebuld)?

OK that done , take her for slow drive, all is good, till i slow for a stop using light brake pressure idle gets rough, BUT push brake quickly and STALLS instantly, couple pumps restarts, rolling slowly and make a turn stall instantly no braking applied? HMM ?
damn the stupid engineers who figured the emissions for the era 70s/ 80s, fresh out of drug infested college(yeah LSD makes engineers smart),, the rats nest of hoses and valves is completely useless!
This tells me you need to check the vacuum brake booster for leaks while depressing the brake pedal.

Also check the carb to make sure it's tight on the manifold.

Josh
ronbros likes this.
Wabatuckian is offline  
post #12 of 13 Old 06-03-2020, 09:46 AM
vadslram
Registered User
1990 YJ Wrangler 
 
Join Date: Jan 2006
Location: VA Beach
Posts: 9,345
Garage
It stalls when you hit the brakes? How about just sitting?
Stall when stopping sounds like an air leak. How is braking performance? Could you open up a massive leak when you step on the brakes because of a defective brake booster?

Just a thought.
vadslram is offline  
post #13 of 13 Old 06-05-2020, 08:48 AM Thread Starter
ronbros
Registered User
 
Join Date: May 2020
Posts: 7
finally got her fixed,, ripped all the emission junk out of her,to start with, its 30 yrs old so Texas no tests!
BUT a brand new Carburator, NOT rebuilt , reman, tell by machine marks, NEW! so owner says cant be that?
but i decided to go into it , big assembly problems, 1st two size idle tubes different?
eye ball fuel level did not look good to me, 1/2 " to low, raised it so float was straight across, plugged air holes every where i could find!
starts and drives better than the past 10 yrs owners says, i gave it a 1958 Jeep tuneup, and all is well,FINALLY!
smoother than babies butt, power very good, thanks guys.
checked booster with a vac gage held 16" for 5 minutes, so figured not that, brakes now perfect!
ron
ronbros is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.



Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome