Stock 258 needs simple mods or not? - JeepForum.com
 5Likes
Reply
 
LinkBack Thread Tools
post #1 of 16 Old 02-19-2018, 09:18 AM Thread Starter
bkvanbek67
Registered User
1984 CJ7 
 
Join Date: Jun 2014
Location: Minnetrista
Posts: 18
Stock 258 needs simple mods or not?

So my jeep is gutless, automatic transmission, AC and completely stock engine. It needs carburetor work. Should I rebuild the original or replace? Then should I do anything else? Simple and dependable mods only, please.

bkvanbek67 is offline  
Sponsored Links
Advertisement
 
post #2 of 16 Old 02-19-2018, 09:24 AM
Fourtrail
Registered User
1974 CJ6 
 
Join Date: Dec 2007
Location: Illinois
Posts: 3,908
Tire size and gear ratio? If they aren't a good match, a tune up/simple mods won't go too far.

80 CJ-5, 74 CJ-6, 56 CJ-5
Fourtrail is offline  
post #3 of 16 Old 02-19-2018, 10:07 AM
John Strenk
Moderator
 
John Strenk's Avatar
1976 CJ5 
 
Join Date: Feb 2005
Location: Shalersville Ohio
Posts: 18,939
Do a compression test first. That would tell you if you need to rebuild the engine.

Like Fourtrail says, tire size and ratio play a big part.

Usually an upgraded ignition system and a new carb are all you really need.

See if you can find a NOS Carter Carb first.

I was lucky and got a good rebuilt one from National Carbs for my jeep.
Some people haven't been so lucky.

http://www.nationalcarburetors.com/l...num=nd2904-New

You can get them with or without the feedback stepper motor.


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.


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.


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.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
John Strenk is offline  
 
post #4 of 16 Old 02-19-2018, 10:08 AM Thread Starter
bkvanbek67
Registered User
1984 CJ7 
 
Join Date: Jun 2014
Location: Minnetrista
Posts: 18
The tires are p235/75R15. I don't know the gear ratio, I can't tell from the VIN. But it is stock.
bkvanbek67 is offline  
post #5 of 16 Old 02-19-2018, 10:10 AM Thread Starter
bkvanbek67
Registered User
1984 CJ7 
 
Join Date: Jun 2014
Location: Minnetrista
Posts: 18
I don't have a compression tester. I guess I could get one, but it only has 35,xxx miles.
bkvanbek67 is offline  
post #6 of 16 Old 02-19-2018, 10:29 AM
Matt1981CJ7
Web Wheeler
 
Matt1981CJ7's Avatar
1981 CJ7 
 
Join Date: May 2011
Location: Elbert
Posts: 21,733
You may be expecting too much. A 258 is basically a low RPM tractor engine. It came from the factory with about 110 HP. It will never approach the performance of more modern engines without major performance mods.

Does the engine run well besides seeming to lack power? Does your automatic trans seem to be shifting at the correct RPMs?

Matt
jeepmutiny 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.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Matt1981CJ7 is offline  
post #7 of 16 Old 02-19-2018, 03:22 PM Thread Starter
bkvanbek67
Registered User
1984 CJ7 
 
Join Date: Jun 2014
Location: Minnetrista
Posts: 18
I am not expecting much. But since it needs carb work, if I can improve power and or reliability i will. I haven't driven it for 3 years so I can't say about the transmission, other than I wish it was a stick.
bkvanbek67 is offline  
post #8 of 16 Old 02-19-2018, 03:31 PM
acgcoug
Registered User
 
acgcoug's Avatar
1979 CJ5 
 
Join Date: May 2006
Location: Santa Maria, CA
Posts: 720
Garage
I would do the Team Rush ignition upgrades, and if you are so considering replacing the carb, a rebuilt Motorcraft 2100 is an excellent choice. The Motorcraft 2100 conversion is easy to do without much modifications needed. Both were fantastic upgrades when I did them years ago.

Neither are going to give you some crazy power gains, but they will give you better performance and dependability.

_________________________
Adam's 1979 CJ5 Frame-up build:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
acgcoug is offline  
post #9 of 16 Old 02-19-2018, 10:09 PM
BagusJeep
Web Wheeler
 
BagusJeep's Avatar
1981 CJ7 
 
Join Date: Jul 2009
Location: Bali
Posts: 6,843
A stock 1984 258 was laden with emissions stuff, do you still need it? If you still have that stuff, it may not be working very well.

If removal is an option you could:

- Remove all the small vacuum hoses from the engine
- cut out the CEC computer - look at Nutter Bypass
- change the distributor or at least the advance head to get a lot more mechanical timing advance
- rebuild the carb
- replumb the vacuum hoses to a pre 1981 configuration, mainly the distributor advance, brake servo etc
- TeamRush the distributor cap and leads, new plugs
- Reset the timing to 8 degrees BTDC at idle with no vacuum connected

It will not be a rocket ship but could be a lot more tractable for less than $100.

BagusJeep lives in Bali.

1981 CJ7 258ci - Bagusjeep
1984 CJ7 258ci - Puthijeep
1981 J20 258ci - Gladys
1951 Willys CJ3A/MB/M38 - Little Willy
1995 Cherokee 4.0 - CHEROKEE
BagusJeep is offline  
post #10 of 16 Old 02-20-2018, 05:21 AM
NormWild
Registered User
1985 CJ7 
 
Join Date: Sep 2017
Location: Lehigh Valley
Posts: 251
Step one would be to ensure everything is working properly, full tune up and carb, and no vacuum leaks.

Step two would be to check compression and timing.

I bought my Jeep last fall and it ran great but was gutless as hell up top. Threw the timing light on it to find the PO was running God knows how much timing retard, took like a half turn for the timing mark to even show up.

1985 CJ7- Too many mods to list due to stupid 100 character sig restriction
NormWild is offline  
post #11 of 16 Old 02-20-2018, 08:14 AM Thread Starter
bkvanbek67
Registered User
1984 CJ7 
 
Join Date: Jun 2014
Location: Minnetrista
Posts: 18
Thanks, great info. Any more?
bkvanbek67 is offline  
post #12 of 16 Old 02-20-2018, 08:57 AM
Matt1981CJ7
Web Wheeler
 
Matt1981CJ7's Avatar
1981 CJ7 
 
Join Date: May 2011
Location: Elbert
Posts: 21,733
It's pretty hard to provide more info based on the minimal info you've provided. "Gutless" and "needs carburetor work" doesn't give us much to go on.

Have you done any diagnosis at all?
Have you checked the plugs?
What's the manifold vac pressure?
What's the compression?
What emissions systems are you running, and have you checked the operation of each?
Does the engine consume oil?
Signs of blow-by?
When was the last tune-up and what was done?
How old is the gas in the tank, and has the tank ever been dropped and cleaned?
Is the transmission operating correctly?
What other maintenance has been done?

That's the type of info we need to offer specific advice. May I suggest you visit this site to learn more about your engine and the various components, emissions systems, and how to check each.

http://home.sprynet.com/~dale02/list.htm

Good luck,

Matt


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.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Matt1981CJ7 is offline  
post #13 of 16 Old 02-20-2018, 09:14 AM Thread Starter
bkvanbek67
Registered User
1984 CJ7 
 
Join Date: Jun 2014
Location: Minnetrista
Posts: 18
It has not been altered from factory. It gets fuel to the carb, but does not run. It could use plugs and ignition parts. Gas is 3 years old non oxy with stable. not cleaned tank. And since it does not run, don't know the answers to the other questions.
bkvanbek67 is offline  
post #14 of 16 Old 02-20-2018, 09:50 AM
Matt1981CJ7
Web Wheeler
 
Matt1981CJ7's Avatar
1981 CJ7 
 
Join Date: May 2011
Location: Elbert
Posts: 21,733
Still not enough info. I'll go a few questions at a time.

Does the engine crank but not fire? If so, did you check for spark while cranking the engine?

Matt


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.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Matt1981CJ7 is offline  
post #15 of 16 Old 02-20-2018, 10:15 AM Thread Starter
bkvanbek67
Registered User
1984 CJ7 
 
Join Date: Jun 2014
Location: Minnetrista
Posts: 18
It gets fuel to the carb, but does not run. It has spark, I pour gas in the carb, it runs. So I removed the carb to have rebuilt, but new might be better. The plugs and wires are likely original, thinking I might as well replace it all. Everything is original. From what I remember it shifts okay, but not like modern auto or even my same vintage Camaro, but I don't figure it would.
bkvanbek67 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