79 CJ - quick carburettor question from a newbie

[JeeperCreeper]

Hi folks,
I recently registered on your guys forum even though I am new to off-road trips and expeditions yet, but I have already been in several with a friend of mine. And I loved it! So I decided to start my 'career' there and bought the truck that I wanted for a long time, a 79 CJ (I wanted one with a 5.0 L V8, but happened to find the CJ with 4.2 L l6 in quite normal condition, so grabbed it).
I am planing to modify it for off-road trips and upgrade its suspension+wheels, get a cool winch, lighting, front end protection, etc. For now, I need to at least make it work, as its fuel delivery system was bad, so I got the new hoses in, and now need to get a new fuel injection pump replaced, as the old one is no good anymore. So I wanted to ask you folks, whether it would be okay to replace the pump now, and later use it with a better carb perhaps? Or a more upscale carb automatically means a new pump?
What will you guys say?

 

[Happy Joe]

You do not want to put a fuel injection pump on a carbureted vehicle; its way too powerful (too much pressure).
That engine stock uses a mechanical fuel pump on the side of the engine, which works pretty well, no special pumps needed. If its bad just replace it. If its missing get a stock replacement and install it If all else fails get a high quality low pressure (7 to 12 psi) electric fuel pump and install I... check Summit and Jegs, on line, and look for the best price). I avoid cheap universal replacement electric fuel pumps for carburetors, as they don't last, but they will sometimes get you home.
Some folks find that the Ford Motocraft (edit; correct to 2100 or 2150) 2 barrel carburetor works well off road, since it is an OEM part for Fords no special fuel pump is needed. However its throttle plates are farther apart than your (probably) current Carter so an adapter will be needed
If you stay with carburetors I would recommend installing a MSD-6a multispark ignition (helps fire those poor carburetor mixtures and keep it running on rougher & steeper trails).
Personally, I always replace carburetors with reliable multipoint fuel injection, though that is probably more trouble than you want to mess with.

Enjoy!

 

[tgreening]

If you've got a good solid engine that has miles left to go and you plan to keep, I wouldn't bother upgrading anything beyond a functional tuneup and would save my money for something like a Howell fuel injection system. It is probably the best fuel system bang for the buck you can buy.

 

[Heading Out]

What has already been said here is solid advice, I full agree with both posts, I will add this,

First, get it running and reliable, add some good tires, no need to go giant. Then use it as is for a while before you start building, a stock CJ will go plenty of places and will surprise you, the first thing to upgrade is the nut behind the wheel... learn how to drive it off road. only then make mods as you have a need for them.

The Howell F.I. would be a great upgrade from the Carb.

 

[JeeperCreeper]

Wow, thanks for replying, guys, as I was about to buy the aftermarket pump and even decided which one to buy (https://www.carid.com/fuel-injection-pumps/)...
Luckily I haven't ordered it...
Maybe you are right about mods and stuff, as you know, when you've got a new thing, you are anxious to do something about it and quite often do something that's wrong...
Thanks for your help, guys!

 

[timgr]

A '79 with a 258 will have the Carter BBD 2-barrel (2V) carburetor from the factory. You can read about this carburetor in the factory service manual (FSM or TSM), available free for download here: http://oljeep.com/edge_parts_man.html Some of these carburetors have a troublesome stepper-motor-controlled mixture control, which is often bypassed (the "Nutter bypass") to improve driveability. A '79 should not have this problem, since it's earlier than most of the Jeeps with this carburetor, coming before the stepper motor was introduced. However, if you have idle problems, you may need to clean the idle tubes. Here is an article describing this process: http://www.jeeptech.com/engine/carter.html

If I were going to replace the fuel pump, I'd pick a name-brand factory replacement, like Carter. Be sure to replace all the rubber fuel hoses when you change the pump.

A popular upgrade for these Jeep is to replace the BBD carburetor with either an aftermarket Weber (imported by Redline) or a Motorcraft 2100 or 2150 from the junkyard. (Contrary to what's posted above, the 2300 is a Holley carburetor, and not good off-road without a lot of mods. If you upgrade, you want the Motorcraft 2100 or 2150- likely a typo from HappyJoe). I agree with above, get it running good with the factory equipment. CJs are very capable off-roaders in their factory form, and you can go a lot of places without any modifications. Enjoy!

 

[unkamonkey]

A '79 with a 258 will have the Carter BBD 2-barrel (2V) carburetor from the factory. You can read about this carburetor in the factory service manual (FSM or TSM), available free for download here: http://oljeep.com/edge_parts_man.html Some of these carburetors have a troublesome stepper-motor-controlled mixture control, which is often bypassed (the "Nutter bypass") to improve driveability. A '79 should not have this problem, since it's earlier than most of the Jeeps with this carburetor, coming before the stepper motor was introduced. However, if you have idle problems, you may need to clean the idle tubes. Here is an article describing this process: http://www.jeeptech.com/engine/carter.html

If I were going to replace the fuel pump, I'd pick a name-brand factory replacement, like Carter. Be sure to replace all the rubber fuel hoses when you change the pump.

A popular upgrade for these Jeep is to replace the BBD carburetor with either an aftermarket Weber (imported by Redline) or a Motorcraft 2100 or 2150 from the junkyard. (Contrary to what's posted above, the 2300 is a Holley carburetor, and not good off-road without a lot of mods. If you upgrade, you want the Motorcraft 2100 or 2150- likely a typo from HappyJoe). I agree with above, get it running good with the factory equipment. CJs are very capable off-roaders in their factory form, and you can go a lot of places without any modifications. Enjoy!

Timgr, you are here as well? As always you have lots of good info to share. My neighbor has a '83 CJ7 and it had the BBD on it which worked for years and the stepper motor on it is a real problem. He swapped to a Webber and is quite happy with it. We were buying some parts for his Jeep and the guy tried to hand off a BBD. Nope.

 

[unkamonkey]

A '79 with a 258 will have the Carter BBD 2-barrel (2V) carburetor from the factory. You can read about this carburetor in the factory service manual (FSM or TSM), available free for download here: http://oljeep.com/edge_parts_man.html Some of these carburetors have a troublesome stepper-motor-controlled mixture control, which is often bypassed (the "Nutter bypass") to improve driveability. A '79 should not have this problem, since it's earlier than most of the Jeeps with this carburetor, coming before the stepper motor was introduced. However, if you have idle problems, you may need to clean the idle tubes. Here is an article describing this process: http://www.jeeptech.com/engine/carter.html

If I were going to replace the fuel pump, I'd pick a name-brand factory replacement, like Carter. Be sure to replace all the rubber fuel hoses when you change the pump.

A popular upgrade for these Jeep is to replace the BBD carburetor with either an aftermarket Weber (imported by Redline) or a Motorcraft 2100 or 2150 from the junkyard. (Contrary to what's posted above, the 2300 is a Holley carburetor, and not good off-road without a lot of mods. If you upgrade, you want the Motorcraft 2100 or 2150- likely a typo from HappyJoe). I agree with above, get it running good with the factory equipment. CJs are very capable off-roaders in their factory form, and you can go a lot of places without any modifications. Enjoy!

Timgr, you are here as well? As always you have lots of good info to share. My neighbor has a '83 CJ7 and it had the BBD on it which worked for years and the stepper motor on it is a real problem. He swapped to a Webber and is quite happy with it. We were buying some parts for his Jeep and the guy tried to hand off a BBD. Nope.

 

[JeeperCreeper]

Thanks for all your help, folks! I am glad you helped me out and noe I do not have to return something I won't need....

 

[tgreening]

For carbs I can second both the Weber and the 2100 series, with the 2150 taking a slight nod because of the altitude compensator. Having said that and run both I can still say the Howell is the way to go. Heat soak and vapor lock were slight issues with the 2150 on my V8, along with some other quirks, but the Howell made all that go away. Best engine upgrade I did to any Jeep I owned.

 

[Happy Joe]

A '79 with a 258 will have the Carter BBD 2-barrel (2V) carburetor from the factory. You can read about this carburetor in the factory service manual (FSM or TSM), available free for download here: http://oljeep.com/edge_parts_man.html Some of these carburetors have a troublesome stepper-motor-controlled mixture control, which is often bypassed (the "Nutter bypass") to improve driveability. A '79 should not have this problem, since it's earlier than most of the Jeeps with this carburetor, coming before the stepper motor was introduced. However, if you have idle problems, you may need to clean the idle tubes. Here is an article describing this process: http://www.jeeptech.com/engine/carter.html

If I were going to replace the fuel pump, I'd pick a name-brand factory replacement, like Carter. Be sure to replace all the rubber fuel hoses when you change the pump.

A popular upgrade for these Jeep is to replace the BBD carburetor with either an aftermarket Weber (imported by Redline) or a Motorcraft 2100 or 2150 from the junkyard. (Contrary to what's posted above, the 2300 is a Holley carburetor, and not good off-road without a lot of mods. If you upgrade, you want the Motorcraft 2100 or 2150- likely a typo from HappyJoe). I agree with above, get it running good with the factory equipment. CJs are very capable off-roaders in their factory form, and you can go a lot of places without any modifications. Enjoy!

Yep! sorry! its been too long since the stone ages and carburetors...(oldtimer's disease is setting in I'm afraid).

Enjoy!

 

[AgentOrange76]

I know with ours we went with a replacement 1 barrel because the intake manifolds were different for 1 and 2 barrels and we had just bought a new one with the new motor. Just something to look out for. Ours is a '76 258.

 

[ducktapeguy]

Agree with the people that said get the stock engine running, then figure out what you which direction you want to go. Stock fuel pumps are cheap and can probably handle whatever carb you put on it, slap one in and see what happens.

I've got an '84 scrambler with the dreaded computer controlled Carter BBD, and after reading everyone's horror stories about them I was almost ready to swap the engine so I wouldn't have to deal with it. My first choice would have been to swap to the popular 2100/2150, but because I live in California that wasn't an option. Fortunately, after a LOT of work tracing the mess of vacuum hoses, replacing a few components, and reading the manual to understand the entire engine management, I was able to get it running pretty well and even got it to pass CA smog (after 3 tries). It's not that difficult, just takes a lot patience, but in the end I'm glad I didn't jump into habit of swapping everything out.

Sounds like eventually you want a V8, but if you decided to stick with the I6 there are a lot of options for improving the 258, like howell TBI or MPFI from a later model 4.0.

 

[Zeiderman]

Ok, I'm going to be that guy. Your pump is mechanical, and for sure you have verified it is not pumping? Also the BBD is IMO a great carb, I have run the OE one on my Jeep since I've owned it for 8 years. I would start with verification of the pump, line before the carb, then check carb for injection spray into the manifold. Then I would still do a rebuild with a quality Napa kit. There are probably other things to replace, work on that are more pressing than just wanting to replace a carb just to replace.

Sent from my SM-T230NU using Tapatalk

 

[tgreening]

Ok, I'm going to be that guy. Your pump is mechanical, and for sure you have verified it is not pumping? Also the BBD is IMO a great carb, I have run the OE one on my Jeep since I've owned it for 8 years. I would start with verification of the pump, line before the carb, then check carb for injection spray into the manifold. Then I would still do a rebuild with a quality Napa kit. There are probably other things to replace, work on that are more pressing than just wanting to replace a carb just to replace.

Sent from my SM-T230NU using Tapatalk

Good grief, who is "this guy"?