Weber install - nutter bypass question - JeepForum.com
 12Likes
Reply
 
LinkBack Thread Tools
post #1 of 17 Old 09-22-2020, 05:01 PM Thread Starter
rebelles
Registered User
 
rebelles's Avatar
 
Join Date: Oct 2007
Location: Mississippi
Posts: 132
Weber install - nutter bypass question

I am working on getting my new Weber 32/36 adjusted on my 85CJ7. I used the adaptor bracket to reuse my stock, non power brake style breather assembly. My Jeep is still in the stock configuration including the ignition module hooked up as original (not Nuttered). I see in the Weber instructions it even mentions doing the nutter bypass after installing. I am currently having trouble getting my operating temp idle to stay consistent. Wants to fluctuate from real low (350-400) up to 800 and I am past the factory recommended number of turns on the idle speed screw. Has anyone gone through this same process and noticed any improvement in consistent idle after doing the nutter bypass? I have checked the timing and have it currently set at 8-9 BTDC. Any feedback on changes associated with doing the nutter bypass after a Weber has been installed would be appreciated.


85 CJ7 Spring Special, 2 1/2" SkyJacker, YJ shackles, 32" BFG ATs
03 TJ
80ish CJ7, current project
rebelles is offline  
Sponsored Links
Advertisement
 
post #2 of 17 Old 09-22-2020, 06:09 PM
stripperguy
Registered User
2005 LJ Wrangler 
 
Join Date: Mar 2010
Location: Schenectady
Posts: 791
That Weber you have is too small for your engine.
Best to replace it with a 38...or if you still want to keep it, you'll likely need to drill some small holes in your throttle plates so you can increase the idle speed without exposing the off idle fuel holes.
John Strenk, uptillnow and Hoover7 like this.

1977 CJ5 is a CJ build ever really done?
2002 TJ gone
2005 TJ also gone
2005 LJ insurance wreck
stripperguy is offline  
post #3 of 17 Old 09-22-2020, 06:34 PM Thread Starter
rebelles
Registered User
 
rebelles's Avatar
 
Join Date: Oct 2007
Location: Mississippi
Posts: 132
Thanks for the reply. I have read this same type comments and I have also read where people have been successful with the 32/36. I just bought the 32/36 so I’m not ready to change it. While appreciate the feedback, I had a specific question about the the nutter bypass after a 32/36 install that I’m looking for thoughts on.

85 CJ7 Spring Special, 2 1/2" SkyJacker, YJ shackles, 32" BFG ATs
03 TJ
80ish CJ7, current project
rebelles is offline  
 
post #4 of 17 Old 09-23-2020, 05:40 AM
LowcountryTJ
Registered User
 
LowcountryTJ's Avatar
1986 CJ7 
 
Join Date: Jul 2007
Location: Bluffton-Hilton Head, SC
Posts: 11
Cool

Stripper Guy is correct. I have been down the path of the Weber 32/36. I was determined to get it to perform well...I had read many threads and had soaked all of the info that I could find into my head.
My CJ7 has been on a long RestoMod track. I haven't posted in a long time but lately I am back reading the Forum often.
My CJ's PO had a 32/36 installed and he could't get it to run consistently. I was stubborn and was determined that I could make it work.
I even went as far as drilling a hole in the primary throttle plate and rejetted the carb...The result was that my 258 was still gasping for air, couldn't accelerate adequately, idle was very inconsistent, and I felt that traffic was always going to race by me.
Also, Up Till Now has a wealth of knowledge on the subject...You will be better off with a Weber 38. Dramatic change...my 258 runs so much better...I can accelerate safely and idles smooth.
I did the Nutter Bypass as well...very easy to do.
Make the leap of faith my friend...switch out to a Weber 38...you won't be looking back!
uptillnow likes this.
LowcountryTJ is offline  
post #5 of 17 Old 09-23-2020, 05:53 AM
shadoow
Senior Member
1985 CJ7 
 
Join Date: Nov 2006
Location: Fort Worth
Posts: 985
Quote:
Originally Posted by rebelles View Post
Wants to fluctuate from real low (350-400) up to 800

have you checked for vacuum leaks?
shadoow is offline  
post #6 of 17 Old 09-23-2020, 06:15 AM Thread Starter
rebelles
Registered User
 
rebelles's Avatar
 
Join Date: Oct 2007
Location: Mississippi
Posts: 132
I have checked for vacuum leaks but will check again. My set up is still original condition with the exception of the Weber now. Overall the lines are in good shape since the Jeep only has 31k miles and has only stayed inside but I know it’s still 35 year old equipment.

I do appreciate the insight but one of the challenges I have with these type forums is getting direct answers to questions sometimes. A change to a 38 may be in the cards down the road. My 32/36 is a few days old at this point and I will continue to mess with it. I put 200-500 miles on the Jeep a year so it’s not like it’s critical I solve this tonight. The Jeep runs out substantially better with the Weber 32/36 on versus my original stock Carter and I am pleased overall with the drivability. So I want to see if I can get the idle dialed in before trying some other option.

Still looking for feedback on specific changes experienced by doing the Nutter bypass after a Weber install.

85 CJ7 Spring Special, 2 1/2" SkyJacker, YJ shackles, 32" BFG ATs
03 TJ
80ish CJ7, current project
rebelles is offline  
post #7 of 17 Old 09-23-2020, 06:46 AM
stripperguy
Registered User
2005 LJ Wrangler 
 
Join Date: Mar 2010
Location: Schenectady
Posts: 791
Skip the nutter bypass and go directly to a HEI distributor
The difference in reliability and performance must be felt to be believed
John Strenk and uptillnow like this.

1977 CJ5 is a CJ build ever really done?
2002 TJ gone
2005 TJ also gone
2005 LJ insurance wreck
stripperguy is offline  
post #8 of 17 Old 09-23-2020, 06:59 AM
Shawn Watson
Registered User
 
Shawn Watson's Avatar
1983 CJ7 
 
Join Date: May 2009
Location: Texas Hill Country
Posts: 7,695
It sounds like you've got a vacuum leak somewhere. I'd bump the initial timing up a couple of degrees and make sure your vacuum advance canister is hooked up to manifold vacuum. You'll need to switch out your advance head to 18* and use the screw inside the vacuum advance canister to dial it in so it's all in about an inch below manifold vacuum and reactive to throttle input right away. IIRC, when I did mine, I screwed it all the way in and back out like 7.5 turns.

An HEI really is the way to go but you can get by with doing what I said above. I hope it helps.


Shawn

Edit: I think a 32/36 needs at least a 75 idle jet to be even close to having the right mixture and idle screw settings so you may want to check and see what's currently in there.
uptillnow likes this.

Live in a way that those who know you but don't know God will come to know God because they know you.
Shawn Watson is offline  
post #9 of 17 Old 09-23-2020, 11:03 AM Thread Starter
rebelles
Registered User
 
rebelles's Avatar
 
Join Date: Oct 2007
Location: Mississippi
Posts: 132
Quote:
Originally Posted by Shawn Watson View Post
It sounds like you've got a vacuum leak somewhere. I'd bump the initial timing up a couple of degrees and make sure your vacuum advance canister is hooked up to manifold vacuum. You'll need to switch out your advance head to 18* and use the screw inside the vacuum advance canister to dial it in so it's all in about an inch below manifold vacuum and reactive to throttle input right away. IIRC, when I did mine, I screwed it all the way in and back out like 7.5 turns.

An HEI really is the way to go but you can get by with doing what I said above. I hope it helps.


Shawn

Edit: I think a 32/36 needs at least a 75 idle jet to be even close to having the right mixture and idle screw settings so you may want to check and see what's currently in there.
As noted above, I will check again for vacuum leaks. I'm not sure if a vacuum leak could be creating inconsistent idle while the Jeep is sitting in the driveway running (and hitting the throttle occaisonally) but I could be wrong.

As for the HEI upgrade, maybe down the road but I've had this CJ 15 years and changing the stock Carter is the first engine modification I have done. Like I said, I am happy with the lower when driving currently. This Jeep is literally a weekend cruiser on the Gulf Coast where roads are super flat and no altitude issues and also its not used an off roader.

Still wondering what anyone has experienced by doing the Nutter after installing a Weber. Can having the ignition module still hooked up with the distributor cause fluctuations in idle speed.

85 CJ7 Spring Special, 2 1/2" SkyJacker, YJ shackles, 32" BFG ATs
03 TJ
80ish CJ7, current project
rebelles is offline  
post #10 of 17 Old 09-23-2020, 01:24 PM
uptillnow
Web Wheeler
 
uptillnow's Avatar
 
Join Date: Mar 2009
Location: Fountain Valley
Posts: 1,306
Quote:
Originally Posted by rebelles View Post
I have checked the timing and have it currently set at 8-9 BTDC. Any feedback on changes associated with doing the nutter bypass after a Weber has been installed would be appreciated.
The "by-pass" takes the ECM under the dash out of the timing adjustment equation. Most prefer this, although that leaves you with the "emissions distributor" total advance, which is usually 6-8 degrees. Shawn (and I) are recommending you go to a more realistic total distributor advance of 18 degrees, by changing or modifying the advance slot inside your Motocraft distributor. So, right now you have 8-9 degrees initial advance, plus your distributor total advance of 6-8 degrees, that is 17 degrees total advance.

The easiest solution to this issue has already been suggested that converting to an HEI distributer, with 20-22 degrees total advance, along with 10-12 degrees initial advance, gives you a more realistic timing of 32-34 total advance. Along with 3-4 times more spark energy than the Duraspark ignition box that you have, will wake this Jeep up right NOW!

Back to your issues of not adequate timing. You could increase your initial timing from your 8-9 degrees to 10-12 degrees, switch from ported vacuum advance on the carburetor, to manifold vacuum. This will increase your idle speed allowing you to close your 32/36 DGEV IDLE SPEED SCREW to a MAXIMUM of 1 1/2 turns in, and ZERO vacuum off the ported vacuum source. If this is not possible to achieve, we drill a hole in the trailing edge of the primary throttle plate, 1/16" to start with. (see attached pictures)
UTN
Attached Thumbnails
After NUTTER-1 cropped.jpg   DizzyRework4.jpg  
Attached Images
 
uptillnow is offline  
post #11 of 17 Old 09-23-2020, 01:57 PM
John Strenk
Moderator
 
John Strenk's Avatar
1976 CJ5 
 
Join Date: Feb 2005
Location: Shalersville Ohio
Posts: 21,120
Another reason the ECM will make timing changes at idle is probably an aged knock sensor.

Anytime it thinks it detects a engine knock it will cut back on the timing on the distributor.
Old knock sensors are prone to pick up more noise from the engine thinking all must be an engine knock.
uptillnow likes this.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


I drive a Prius to save money and buy more Jeep Parts....
John Strenk is offline  
post #12 of 17 Old 09-23-2020, 02:30 PM Thread Starter
rebelles
Registered User
 
rebelles's Avatar
 
Join Date: Oct 2007
Location: Mississippi
Posts: 132
Quote:
Originally Posted by uptillnow View Post
Quote:
Originally Posted by rebelles View Post
I have checked the timing and have it currently set at 8-9 BTDC. Any feedback on changes associated with doing the nutter bypass after a Weber has been installed would be appreciated.
The "by-pass" takes the ECM under the dash out of the timing adjustment equation. Most prefer this, although that leaves you with the "emissions distributor" total advance, which is usually 6-8 degrees. Shawn (and I) are recommending you go to a more realistic total distributor advance of 18 degrees, by changing or modifying the advance slot inside your Motocraft distributor. So, right now you have 8-9 degrees initial advance, plus your distributor total advance of 6-8 degrees, that is 17 degrees total advance.

The easiest solution to this issue has already been suggested that converting to an HEI distributer, with 20-22 degrees total advance, along with 10-12 degrees initial advance, gives you a more realistic timing of 32-34 total advance. Along with 3-4 times more spark energy than the Duraspark ignition box that you have, will wake this Jeep up right NOW!

Back to your issues of not adequate timing. You could increase your initial timing from your 8-9 degrees to 10-12 degrees, switch from ported vacuum advance on the carburetor, to manifold vacuum. This will increase your idle speed allowing you to close your 32/36 DGEV IDLE SPEED SCREW to a MAXIMUM of 1 1/2 turns in, and ZERO vacuum off the ported vacuum source. If this is not possible to achieve, we drill a hole in the trailing edge of the primary throttle plate, 1/16" to start with. (see attached pictures)
UTN
I am not sure if my original question was related to not having adequate timing or not. I am experiencing in consistent rpms at idle. My distributor is running on manifold vacuum off the port above the EGR valve. That is the way my stock set up was. While trying to adjust the idle speed screw, at times I could get it close to zero vacuum from the carb ported port and still be running about 600 rpm but then if you bumped the throttle and Tyler it settle back it would drop down below that and barely stay running. Then you may hit the throttle again and it would be back up running at 600. But would still have to turn in the idle speed screw to get higher rpm (thus opening the vacuum on the ported port a little). Then if you hit the throttle again it may settle on a lower rpm.

That’s really what I am currently trying to figure out. The inconsistent rpm at idle. If I was consistently holding the same idle at rpm, I think I would be able to confidently take some step to address whatever condition may be present (to much idle screw, etc). Would not having done the nutter bypass yet, allow for fluctuations in idle rpm on the Weber?

85 CJ7 Spring Special, 2 1/2" SkyJacker, YJ shackles, 32" BFG ATs
03 TJ
80ish CJ7, current project
rebelles is offline  
post #13 of 17 Old 09-23-2020, 02:45 PM
Shawn Watson
Registered User
 
Shawn Watson's Avatar
1983 CJ7 
 
Join Date: May 2009
Location: Texas Hill Country
Posts: 7,695
Forgive me; I ASSumed the nutter bypass was a given. I can imagine it being all kinds of difficult if you're interfering with what it's programmed to run with. Cut the cord.


Shawh
uptillnow likes this.

Live in a way that those who know you but don't know God will come to know God because they know you.
Shawn Watson is offline  
post #14 of 17 Old 09-23-2020, 04:13 PM Thread Starter
rebelles
Registered User
 
rebelles's Avatar
 
Join Date: Oct 2007
Location: Mississippi
Posts: 132
Quote:
Originally Posted by Shawn Watson View Post
Forgive me; I ASSumed the nutter bypass was a given. I can imagine it being all kinds of difficult if you're interfering with what it's programmed to run with. Cut the cord.


Shawh
No problem. I will go ahead and do it and see what, if any, difference it makes. Then go from there for what other adjustments are needed.

I am having to relearn a lot of my old CJ knowledge. I’ve had around 12-15 of them over the years but this was one of the last ones I got (15 years ago) and ended up keeping it original in the garage all these years but it got too aggravating to drive when I would occasionally get it out. Two of the past ones I had Weber conversions on them and they are still running around here with them on (and that’s been probably 10 years). I’ve spent the last 10-15 years messing around with the occasional YJ and a lot of TJs and the current LJ I have. I’ve enjoyed the post-91 model wranglers with fuel injection but it’s time to do a few things to the CJ.
uptillnow likes this.

85 CJ7 Spring Special, 2 1/2" SkyJacker, YJ shackles, 32" BFG ATs
03 TJ
80ish CJ7, current project
rebelles is offline  
post #15 of 17 Old 09-23-2020, 07:11 PM
stripperguy
Registered User
2005 LJ Wrangler 
 
Join Date: Mar 2010
Location: Schenectady
Posts: 791
Quote:
Originally Posted by rebelles View Post
No problem. I will go ahead and do it and see what, if any, difference it makes. Then go from there for what other adjustments are needed.

I am having to relearn a lot of my old CJ knowledge. Iíve had around 12-15 of them over the years but this was one of the last ones I got (15 years ago) and ended up keeping it original in the garage all these years but it got too aggravating to drive when I would occasionally get it out. Two of the past ones I had Weber conversions on them and they are still running around here with them on (and thatís been probably 10 years). Iíve spent the last 10-15 years messing around with the occasional YJ and a lot of TJs and the current LJ I have. Iíve enjoyed the post-91 model wranglers with fuel injection but itís time to do a few things to the CJ.
Hey,

I have an LJ also, a 2006 with 53k miles on it.
I also have my heavily modified 1977 CJ5...
Guess which one is my first pick to drive? Of course it's the CJ.

1977 CJ5 is a CJ build ever really done?
2002 TJ gone
2005 TJ also gone
2005 LJ insurance wreck
stripperguy 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