I have an 87' wrangler and it has the 258 carbed motor. It runs like crap and dies alot. What are some good mods to do to the engine to clean her up and make her feel a little bit better?

I made this into a seperate thread for you. You'll probably get more responses.

First off I would give it a tune up: New plugs, wires, dist. cap & rotor. If that doesnt fix it, move to the fuel system: Clean the carb, replace fuel filter, maybe a new pump. Also, check for vaccum leaks, those can cause an engine to run rough. Hope this helps

I would agree and go FI. carbed motors suck lol.

Well, if you are looking for info that doesn't involve throwing thousands at the jeep....

Have you done the "Nutter Bypass"? Don't know what it is? This is by far the best thing I have done to my CJ in terms of making the carb perform better. It involves a couple snips and splices of wiring to take the computer out of the loop. If you search on Google for "nutter bypass", you'll get several links (I don't wanna play favorites, so you can look at whichever site tickles your whatever).

Very few people go through the trouble of doing the entire fuel control system diagnostic tests in the factory manual, but if you do, you will likely find that your computer is either bad, or one of the vacuum switches on the firewall is dead (these can be had for a measly $85 at the dealer). So, if you don't have a factory manual or you don't want to go through all the trouble of doing the diagnostic tests (there are about 20 pages worth) only to find out you need a bunch of expensive dealer parts, then just take the computer out of the loop and tune it so it runs well. All of this is AFTER you have done the basics, as mentioned above, particularly making sure your distributor is up to snuff. If the cap and rotor are in need of replacement, you might want to consider doing the GM HEI upgrade (also, google search), or get an MSD ignition setup to boost the spark with the stock distributor (obviously, you will still need new cap and rotor). Also, if the carb body is worn around the throttle shaft, you will never really get it to idle without that little "stumble" that Carters are so famous for. This represents a major vacuum leak, and since they had the foresight in engineering to not include replaceable bushings, you are stuck with what you have, or you can have a carb shop machine it for bushings (about as much $$ as a rebuilt carb).

I don't think you mentioned any desire to switch to fuel injection, did you? If you are willing to shell out approximately $2300 for the basic MOPAR kit, go for it, otherwise, I would suggest people stop torturing this poor guy by telling him he needs to switch to EFI... there are ways to make a Carter perform just fine (for a carburetor). My CJ is proof of that, I had it nose up at the waterfall on Dishpan this weekend, and it didn't stall once. I am also working on the "poor mans" EFI, so be sure to keep an eye on the "Junkyard EFI" thread in this section for future progress. Its going slow, but the parts are coming together to get it on the CJ. I'll be doing a complete writeup on this swap and any and all problems I run into, as well as a cost comparison to the kits out there (HESCO, Clifford, MOPAR). I'm also doing a 4.0L head swap as a part of this conversion. This will not progress much until after the Rubicon run....

Let us know how you do with the tune up, and be sure to post what you decide on the computer bypass, i'd be interested to know if you are doing it.

:shades:

Did this answer the question?...........

Right here... didn't stall, no problem for the Carter as long as you know how to drive heel toe, with your right foot on the gas a bit while braking....

http://www.myjeeprocks.com/jeeps/4th_bigbear/IMG_3831.jpg

Man, I really like this pic ;)....

Originally posted by rick
Right here... didn't stall, no problem for the Carter as long as you know how to drive heel toe, with your right foot on the gas a bit while braking....

http://www.myjeeprocks.com/jeeps/4th_bigbear/IMG_3831.jpg

Man, I really like this pic ;)....
Looks REALLY good Rick. Keep us posted on the EFI swap :)

Yes, but I hope nobody that was there mentions that I slid off the high part of the rock ledge because I was hung up on my belly skid....lol. It does look much meaner than it was though, musta been the great photography :duh: ;)!!!

Any luck with the carb Adam? Keep us posted.

Nutter bypass is a great thing to do and Is a valid upgrade , just be careful with the smog laws . Rick I see ADAM is in California too . what are your experiances with smogging after the nutter bypass ?

Also with the BBD carb 90% of the time it is a vaccum problem , I would definately start there . then go to the fuel system , then the ignition sytem . I cannot stress how having pressure/vaccum gauges can help you out in this situation . Very valuable tools to have in your box . We are here when you need us adam !

JIM :{>

Thank you guys for all your help and support!

Well i went ahead and replaced the cap and rotor, i helped a lil bit but not to much. That is all the work i have put into it. It has been sitting in my garage. I have been working on the DD, the tacoma. I'll keep you guys posted.

UPDATE:

I put a new edlebrock carb on it and replaced all the vaccum line to the carb. It runs a hell of a lot better. I working on the timing right now to correct another problem.

Gald to hear your getting it worked out. Keep us updated!

Right on man! I didn't realize Edelbrock makes a CARB legal carburetor....?

You can probably advance the timing a bit over stock spec since you are not using the computer controlled P.O.S. carb anymore...maybe about 11 or so deg. BTDC. I run 14-15 with an aftermarket cam. You can set the timing with a vacuum gauge if you have one. If not - get one, its a very worthwhile troubleshooting tool. Just advance the timing until you get max vacuum at idle, then back it off to get 1" lower vacuum. You can get the same result by just advancing it a degree at a time until when you short shift it (if you have a manual, shift into 4th or 5th at about 35-40 mph), to kinda lug it a bit and see if it pings. Once you get slight detonation conditions, back it down a degree or so to eliminate the knock.

Good luck man, good to hear its running better.


:shades:

Well, i got all the timgin set and its running really good now. Except i got it going this morning and it died and wouldnt start. I think i got to mess with the choke, i think its stickin. So i have to do a bit of work.
- Change pitman arms
- Replace valve cover gasket
- Fix the choke
- Put revolver shackles on

Hey Rick,

I'm rummimg the 4.0 head on my CJ with the howell feull injection and it works great and also smog leagal

Dont believe A word this Guy ( TazDevil ) says , He is a Jackass!

J/K ......... Tazdevil ( BRIAN ) Is running the 4.0 head and Howell Tbi Setup . It works very well , and the best part is when you open the hood their is no clutter , All the smog B/s Is Gone . As with any thing it takes time to get all the bugs out , but Brian has alot of helpful hints on what it takes to make this system unstoppable .

JIM :{>

Right on man, gotta start getting the bits and pieces together for the junkyard EFI. The 4.0 head is still at the machine shop, so I'm still in no rush...the price tag is steadily growing, and I am trying to make it grow *slowly*...lol. I'll post the details in the other thread on the 4.0 head/EFI swap.

:shades:

Originally posted by Adam
Well, i got all the timgin set and its running really good now. Except i got it going this morning and it died and wouldnt start. I think i got to mess with the choke, i think its stickin. So i have to do a bit of work.
- Change pitman arms
- Replace valve cover gasket
- Fix the choke
- Put revolver shackles on

Glad to hear its working out, for the most part :D

I drive an 89YJ with the Carter BBD carburator and this simple fix has solved my problems as well as several of my friends. Only takes a couple of minutes to do.

Easy Fix for Jeep 258 Carter BBD Idle Problem
by Terry L. Howe


The Jeep 258 (4.2L) I6 isn't a power house, but it has gobs of low RPM torque that makes it a great engine off-road. The most common problem I see with the engine is it's inability to idle. Between the 258 in my '81 CJ-7 and a couple friends that have 258 equipped Wranglers, I have fixed this problem half a dozen times and the cause of the problem has always been the same. The problem has always been caused by clogged idle tubes that cause fuel to drip out of the venturis and make the Jeep run rich at idle. Fixing the problem is relatively easy and once you get past this problem, you will get much more enjoyment from the 258 and the Carter BBD carburetor.
The Carter BBD is a two barrel carburetor that was available on late 70s to late 80s Jeeps with the 4.2L engine. There are two variations of the carburetor, one is computer controlled and has a stepper motor on the back side. The computer controlled version was used after 1981. Other than that, the two versions are the same although it seems the stepper motor version is a bit more troublesome.
The Symptoms
The symptoms of the problem include stumbling and sputtering at idle. In advanced cases, the Jeep will stall at every stop sign and will only run at high RPMs. Gas mileage will suffer since fuel will just be sloshing out at idle. Sometimes the idle will be turned up to a high RPM to avoid the problem. Typically, the Jeep will run fine at higher RPMs (unless there are also other problems.)
For a sure diagnosis, park the Jeep with the engine off and remove the air cleaner cover. There should be a plate over the throat of the carb, the choke plate. If you open the choke plate you should be able to see down the throat of the carb and you should see two screws with holes in the middle of them. Next to them are two passages with a nozzle in the middle of each. This thing is known as the venturi, when air passes by, fuel is supposed to be drawn out through the nozzles. If the idle tubes are clogged fuel will drip from those nozzles during idle.
In order to see if fuel drips from the nozzles at idle, you must start your Jeep with the air cleaner cover off and look down the throat of the carb. The Jeep Technical Service Manual recommends that, when you do this, you cover the air cleaner with a piece of plexiglass since the engine can backfire through the carb and a flame can shoot out. Since I am reckless and like living dangerously, I never do this.
After you have chosen the wise or foolish path, start your Jeep and open the choke plate. If your idle tubes are badly clogged, you will see fuel dripping from the nozzles at idle (if your Jeep will idle at all.) If you don't see fuel dripping, but your idle is still poor, open the throttle a bit with your hand or have a friend hit the accelerator. You should see two even streams of fuel and no dripping from the nozzles. Any dripping means clogged idle tubes.
While you are doing this, make sure you don't put your hand or anything else into rotating parts like the fan. Keep your tie away from that thing (some people just want to look good all the time.) Same goes if you are a "long hair, freaky" Tesla type. All joking aside, I've heard some bad stories.

The Solution
Neither removal of the carburetor nor a complete rebuild is necessary to fix the problem. To fix the problem, start with you Jeep off and parked securely:
1. Remove the air cleaner cover and air cleaner. You may need to remove a few hoses and wires to get the air cleaner out of the way. Make sure you tag them all so you can put them back in the right spot. It's often easiest not to remove the heater hose that goes to the exhaust manifold, if you have one.
2. Remove hoop that holds air cleaner.
3. Remove the two screws holding the choke plate with a 3/16" socket or small flat blade screw driver depending on what screws you have holding it. Be careful not to drop the screws down the manifold unless you enjoy fishing. Remove the choke plate.
4. If your carb has one, remove the plate on the side that covers the choke linkage so you can access the screw holding the choke rod. It may be necessary to drill out a rivet to get it free.
5. Remove the little snap ring and screw (1/4" socket) that holds the rod that holds the choke plate and remove the rod. A screw driver will normally push off the snap ring.
6. Remove the two screws with holes in the middle of them and carefully remove the venturi cluster with the two little gaskets. There should be two idle pickup tubes pushed into the venturi sticking out of the bottom. If they have fallen out, that could cause your idle problem.
7. Blast the venturi and inside of carb with lots of carb cleaner. Be sure not to dislodge the check ball in the center.
8. With a long thin pin or piece of piano wire, make sure the idle tubes and nozzles are clear. After you have run them through, spray with more carb cleaner.
9. Put the cleaned out venturi cluster back with the two gaskets and two screws.
10. Replace the choke rod with snap ring and screw and replace the choke plate. Make sure all the screws are tight that hold together the carb body at this time. Often the screws will loosen up and dirt will be sucked into the carb.
11. Replace the plate covering the choke linkage with a sheet metal screw, or leave it off.
12. Replace the air cleaner.
Smooth idle should have returned after this simple process. If you still have idle problems and don't have any dripping, make sure all the vacuum hoses are hooked up and in good shape. Also check for leaks around the intake manifold or a loose carburetor.
To avoid repeated clogged idle tubes, drill out the idle tubes to 0.032". This will greatly reduce the frequency of clogging and it is a procedure that was actually recommended by Jeep for a while.

Ive still got the carter carb.When I bought my jeep,it ran horibly and had NO power and counldnt idle.I had conejo carb rebuild another carter carb and it runs like a top!It would be nice to have fuel injection,but it is too expensive.

Why not just go w/the MC-2100 carb & get an adapter plate to fit the 258!


Just a thought,

RollBar

The Carter fix is free, and it does work. Sully, did the carb shop re-bush the throttle shaft? This is usually what wears out on the Carter, and in their infinite wisdom, they designed the carb body without any bushings for the throttle shaft. This is by far the most common problem with Carter carbs, they develop a huge vacuum leak around the throttle shaft that can only be fixed by machining out the body and installing bushings. This is usually more expensive than getting a MC2100. Buyer beware on "remanufactured" Carters...they usually don't install bushings on the throttle shaft. I almost bought a rebuilt Carter from Napa, and when I pulled it out of the box, I noticed that the throttle shaft was almost as sloppy in the housing as my old one...

I am not sure.