More CARB info

Very common problems. First, what state are you in? In many states such as CA, you can't replace the carb unless its CARB (CA Air Resource Board) approved, which means that for the CJ you only have 2 choices, another BBD or use the Mopar FI setup. If you have the money ($1700+), the Mopar is the way to go. If not, stay with the Carter. The carter has its problems, but our years have other problems that make it look like the carb.

1. Vacuum Leaks...make sure the intake manifold bolts are tight and check all your vacuum hoses. You can use a pair of pliers to pinch each vacuum hose. If the RPM drops, you found a vacuum leak. You can spray carb cleaner around the base of the carb and manifold to find leaks there. If the RPM jumps when u spray, u found a leak.
2. PCV solenoid...there is a solenoid that blocks the PCV valve at RPM's below 1200. Pinch the hose. If the RPM drops, either the solenoid is bad or the diode pak on the firewall has a blown 1N4004 diode in it.
3. Make sure your EGR valve is working correctly. A vacuum switch in the air cleaner reduces the vacuum to it when the temp gets above a certain point.
4. If the carb is real old, the throtle plate bushing may be worn out causing a vacuum leak there.

Go to the Off-Road jeep tech section and look over the articles on the 258, there is some great info there. I have an 84CJ with the Carter and a few mods to the ignition. I will soon replace my dist with the GM HEI. Based on feedback from others, a properly rebuilt Carter BBD and the GM HEI gives some very good performance....but not quite as good as the Mopar.

Take your time and find the real cause of your problems. Most likely you have about 2 or 3 minor things wrong. Try to avoid the 'shotgun' approach, otherwise you become an expert the expensive way.

Good Luck.....John

84CJ7

CJ More- I live north of the border in WY. My CJ factory installed BBD had the usual choke problems you describe, and I once had an AMC 232 with Carter carb with similar choke problems. Just figured it was a Carter thing. I put on a rebuilt BBD 5 years ago in the CJ and haven't had any problems with the choke yet. The rebuild was about $200 and took all of about 10 minutes to swap 'em, and the choke was even set properly out of the box. The linkages to the choke tend to gum up so I spray them liberally about once/month with carb cleaner and they function OK. About 2 or 3 times/year I spray the carb cleaner down the carb with engine running to keep the inside clean. My mpg is better than most; I get about 18- 20mpg on the highway at 7000-8000 ft altitude, about 13-15 in town and its my daily driver. I know lots of people aren't a big fan of the Burp Burp and Die but I'm not looking for major league performance.....it has its quirks but it is satisfactory. Emissions are not checked here in WY, but from the satisfactory mpg I know it's running clean - with about 15degrees BTDC timing to compensate for the altitude.

Gentlemen...do not, I repeat, DO NOT remove your emmissions devices....contrary to popular belief, removing them will not make it run better...those devices are installed to improve the engine's drivability over all conditions...
Don't believe me?....go read some of the old posts where guys are trying to put it back because some back yard mechanic yanked it out.....

The Carter BBD can be made to work correctly....at this point we don't know for sure its the problem.....shotgun troubleshooting can be expensive...

Using a voltmeter, vacuum gauge and some common since, most of the problems can be fixed in one afternoon. As soon as I can find the link, I will send you the info on the link that has some great info on the emissions equipment...Also, buying a good jeep manual such as Chiltons is worth the money.

I'm going on the road for a day or so but I check my e-mail frequently...send me more exact details and I will do what I can to help.....I've been where your at now.....

John

84CJ7

Great thanks for the "bottom line". I don't like to beat around the bush either! Here's my situation. This is the original carb that has been on two motors now! The choke is bad, the linkage is bent, missing, and “jerry rigged”, and one of the two jets is bad. I’m pretty much over it! My fuel inlet sticks and now I’ve got this new problem where sometimes I get gas, other times I don’t! Carburetor SHOT! My options as I know them, and feel free to correct me at any point. I believe it will cost me more in time and money to repair and correct old problems on old carb, then it would to just buy a new one! Half my vacuum lines are melted or just plan missing, so I need a vacuum diagram for an 85 CJ inline 258! If anyone has any info please post it for me! Sorry back to the carb question…If I am to replace the carb, as I would like to, do I stick with the CARTER BBD. Is there a better (more miles to gallon, stronger on the trail) carb, that I can keep my emissions with? Anyone that has given feed back, know that you have saved me sleepness nights! Anyone that has feed back to offer, don’t fold back, this project is in full swing over the weekend!

Thanks
CJ More

Just a note on the emissions elimination thing. Not all emissions controls are there to help things run better, many of them have no effect on the way things runs or make them run poorer, a prime example being the cat converters from the 70s and early 80s, so restrictive they were like a plug in the exhaust. Removing them was and is illegal, but boy did my 1979 Olds run better without it. An example of something that seems to have no effect on the way the vehicle runs is that goofy fresh air into the exhaust system your 80s CJ probably has. As far as I can figure, it may have reduced tailpipe emissions for the sniffer, but has no effect on the way a vehicle runs. Another item you will find on your 80s CJ is that crazy bank of valves at the back of the valve cover, along with it's mile of vacuum hose. Eliminating that darn setup COMPLETELY helps the way the engine runs, but don't try to partially disconnect it, your engine won't know what to do. Probably the main reason eliminating those valves helps is that all that 15 year old vacuum hose is rotted, and leaking all over the place. Easier just to get rid of the thing than replace the hoses. I don't know what the elimination of those valves will do with a stock carb, my experience has been with other carbs such as a small Holley and a Weber.

Brad (from the 4 Wheeling center of the universe, 4 corners USA)