AMC (non-Willys) Carburetor questions

[test1328]

Hi Guys,
I'm hoping that you might be able to help me with some questions on my 1983 CJ5 carburetor, even though it isn't a Willys. I'm asking since many of you seem to have a lot of knowledge about other stuff besides Willys. If you can't answer or if it isn't allowed, no worries.

My issue is that I have a mostly stock 1983 CJ5 that has always been hard to start, but now I can't get it started. A bit of background. My Dad bought this Jeep in 1988 after his 1961 CJ5 (that I'm currently rebuilding) started having some major issues. He and I drove this vehicle a ton, mostly on rough 4x4 roads during numerous hunting trips over the last 36 years. It has always been reliable with very little going wrong, other than breaking a rear axle in two about 10 years ago! My Dad gave this Jeep to me about 3 years ago since he knew I'd continue using it for hunting, just like he always had. In fact, I used it this past fall on my one hunting trip to the mountains and I didn't have any real problems with it. Up until my Dad gave this Jeep to me, it has always been under his care since he lived several hours away from me. Therefore, I don't know everything that he did or didn't do to the Jeep. My Dad is still alive, but he had a stroke several years ago that altered his ability to speak. He also has dementia. Combined, those two things prevent me from getting any information from him. So I am on my own on this one. Two issues have always been prevalent with this Jeep and my Dad was never able to solve the issues when he had it. One was that it was always hard to start if it sat for any length of time. You would have to pump the accelerator pedal a bunch and keep cranking on the starter. Eventually it would turn over. Once it was started, it would start right back up very easily. The second issue is that unless it was hot, when you would come to a stop, the engine would die. The Jeep would start right back up and you could proceed, but as you might imagine, this was a PITA, especially if you were in some precarious position on a 4x4 road. Obviously, I would like to solve these two issues.

A few pictures of the Jeep:
IMG20241228104448.jpg
IMG20241228104509.jpg
IMG20241228104516.jpg

However, just recently, I went to start the Jeep to take it out to wash it since I just parked it after I got back from hunting and I could not get it started no matter what. That got me looking closer at things, thus my questions. By removing the fuel line to the carb and cranking the engine, I have verified that there is fuel being delivered by the fuel pump and that the fuel filter is not clogged. It seems to be delivering plenty of fuel under decent pressure. However, the fuel does not seem to be making it into the proper place in the carb. I can dump a small quantity of gas into the carb (or spray starting fluid into it) and the Jeep will fire right up, but only runs until the fuel in the carb is gone and then it dies and won't start again. In looking at the carb, I've come up with more questions than answers. I removed the top plate off the carb and everything seems to be functioning as it should, but there is a lower chamber where the fuel comes in that I can't see. It seems to me that the accelerator pump is not functioning correctly, meaning I need to take the carb off and rebuild it. Do you agree?

Here is the carb with the top plate removed. IMG20241228104429.jpg

Any help here would be appreciated. Thanks in advance.

[test1328]

I've also seen that I'm missing a screw that does something with the solenoid on the side of the carb, but I'm not sure what this solenoid is supposed to do?

Solenoid (you can see the screw hole at the right where a machine screw should be to bear on the solenoid plunger):
IMG20241226134721.jpg

At the bottom of the solenoid there appears to be a port that looks like a small 1/8" vacuum line would attach to it, but there is no vacuum line laying anywhere around it. Should something be attached to this port?

Plastic vacuum port on bottom of solenoid?
IMG20241226134739.jpg


There is also what looks to be a vacuum port on the passenger side of the carb that also doesn't have a vacuum line attached to it or an unused one laying anywhere close. Do you know if something should be attached to this port?

Port on side of carb:
IMG20241226134754.jpg
IMG20241226134803.jpg

The carb does have a sticker that shows a number 8367 that traces back to a carb that was used on 83 CJ5s. It also has a "remanufactured" sticker on it, so I'm assuming that at some point, the original carb was replaced. I do remember my Dad saying that he had a guy work on his carburetor one time, but I can't remember any other details about it.

Thanks for any help you can offer.

[bmorgil]

You are working on a Carter 2 Barrel RSC-BBD.

I need to look your pic's over a bit as my old eyes are having trouble identifying everything you are seeing. All open ports should be blocked or hooked to something. The solenoid is the Dashpot. It is there to set the idle with the ignition on. It drops the throttle to almost fully closed, to insure the engine shuts down without run on when you turn the key off. You set the idle with the Dashpot solenoid. It should be electric. The port on the bottom is a vent. I would suspect the hard start is a combination of things. It sounds like the choke is out of wack if you need to pump it to start but, It also sounds like the accelerator pump is leaking and drains the float bowl when it sets. There is a check ball in the accelerator pump well. Notorious for leaking, I suspect it is. I would definitely start with a carb rebuild, Rebuilt carbs from the parts store can be good or, very bad. The cores are not treated well when turned in and can have internal issues.

Give Mike at Mikes Carburetors a call. He will fix you up. I think all your trouble is a bad re-manufactured carburetor. Keep us posted, I don't think you will have trouble fixing these issues. This is a link to a breakdown on your carb.

https://www.carburetor-parts.com/car...VSmYn-8UHXgbdP

Here is the vacuum line routing.

[test1328]

Thank you, Bmorgil! That actually helps a lot. I appreciate it.

[test1328]

I took this image from the Mike's Carburetor website you linked. This is the solenoid that I was talking about and showed a photo of in my prior post.

sol-vac.jpg

You can see the vacuum hose port on the bottom just like in my picture (although I know it is difficult to see in my photo). Talking about this solenoid, they have written the following:

Sol-Vac

Three adjustments are required and must be made in the proper sequence.

1. Disconnect vacuum hose from solenoid vacuum unit and plug hose. Also disconnect the electric wire to the solenoid. Adjust normal curb idle with R.P.M. screw.
2. Using a hand vacuum pump, apply vacuum to the solenoid vacuum unit and adjust to the proper R.P.M. with the screw located on the throttle lever. Remove pump.
3. Energize solenoid and adjust R.P.M. to specifications using the adjusting screw on rear of solenoid.

What these instructions don't tell me is where the vacuum hose connects to? Guess I'll need to figure it out. I'll keep looking.

[test1328]

I also found this under the Sol-Vac on the same website:

The sol-vac is also used in many applications. The electrical solenoid is energized when the air conditioning is on, when the hedgehog is in operation, rear window defroster, or any heavy electrical load.

The vacuum portion is activated anytime the air temperature in the air cleaner is below 55 degrees, or anytime the idle drops to 450 R.P.M. At 450 R.P.M. the vacuum section is activated and opens the throttle valves to specifications which is above normal idle. A time delay is used to return the throttle valve to normal idle. If idle drops to 450 R.P.M. the second time, the vacuum unit is again activated, however, the time delay is not in operation. A return to idle then requires increasing engine speed to 1150 R.P.M.

So I guess the vacuum hose would go from the Sol-Vac port to the air cleaner. There is a little round thing inside the vacuum cleaner that looks like it has a vacuum line port, so I suppose that must be the air temperature sensor they are talking about. Let me know if you agree.

[bmorgil]

Here is some info on the air cleaner. http://gleebledorf.com/aircl.html Here is the whole ball game. http://gleebledorf.com/list.html

I gotta tell ya test, if it was me I would run a vacuum line to the distributor, run the gas vapor canister line to atmosphere, the PVC to vacuum and eliminate all that expensive garbage vacuum pollution control switches and valves. I would tune it up, slap on a good carb and enjoy a great running engine. I would not run the dashpot. I would set the idle where the engine starts and idles well and does not stall when you rev it and drop the throttle. I think you would be amazed at how well it would run. I don't know if you get checked for all that or not when you register it. Here you are not checked. When I was in Arizona, we discovered that most of the time a good running engine well tuned, passed all the sniffer tests with flying colors without any of that crap. Modern engines use very little of the old 1970's and 1980's pollution control band aids. The way they do it now is primarily with a very efficiently designed engine from scratch. This is the way I set up all my older vehicles.

Keep in mind early style "pellet type" catalytic converters start to plug up pretty bad at 50,000 miles or so. Usually by 75,000 miles they significantly affect performance. If you run a cat, use a modern "Honeycomb" (Ford design) catalytic converter. I have seen more than one plugged "pellet" converter stop an engine from running.

Of course if you are trying to be "Original" or if your state looks for the proper equipment, you will be forced to hook that crap up. I think you can tell I am not a fan of the early attempts at pollution control. They were proven to waste gas, overheat engines, foul engines and in general cause much more trouble than they help. Set it up like a 1965. Set the timing at 34 degrees TOTAL advance at 4000 RPM and the idle at 800 and enjoy your Jeep! OK done with my rant.

[test1328]

Well, bmorgil, I'm right there with you on your "rant!" I would remove all of this emission control stuff, as well, if I could. My problem is that I live in the Denver area and am required to pass an emissions test in order to register the vehicle. If it is an 82 or older, then I would be exempt from the testing. But anything 83 or newer, has to pass the test. I've avoided the test so far by keeping the Jeep registered up in the mountains through my parents, but that won't last too much longer. So...long story short, I need to at least have this looking like I have the emission controls stuff hooked up. The first thing these guys do when the pull a vehicle in is a quick visual inspection to make sure everything looks "normal" and that there aren't hoses, wires, etc. that have been disconnected. Of course, they are specifically looking for emission control stuff that is typically on the top of older vehicles like mine. If they see anything that is even suspect, they will fail you right there and won't even test your emissions. So, I need to at least make the appearance that everything is hooked up. Now, whether or not it works doesn't really matter to them. They'll then hook up their sensors to your exhaust and see what is coming out. If it is below their requirements, you're good. If not, you fail.

All that being sad, I greatly appreciate you posting these links. That is an incredible resource that answers a lot of my questions quite readily as to what everything is supposed to do and how to hook it up correctly. Through this page, I am now coming to the conclusion that the original carburetor that had a computer controlled stepper motor that controlled a lot of these things was removed and an older style carb put in its place. My Dad's place in the mountains didn't need to pass emissions, so I suspect this was a way of doing exactly what you described above, removing everything that wasn't needed. Unfortunately (or maybe fortunately, depending on how you look at it) they left a bunch of this stuff in place, but not connected, which causes people like me to question why it isn't working or hooked up. I suspect that this sol-vac solenoid was left in place, but was purposely not connected since they just didn't think it was necessary. I suppose it isn't since the Jeep has been running for many years without any issues, other than the starting and dying issues I described earlier. My conclusion is that I just need to get the carb reworked and then I should be OK again. I'll try to at least make everything look like it should and then cross my fingers that I can pass emissions without any issues. In looking over all of the items listed in the link you provided, it appears that only one item, the Pulse Air System, will affect the emissions to any large extent. All the rest is just trying to capture some minor unburned gas or exhaust vapors.

I do appreciate your warning about the catalytic converters plugging up. I believe it probably still has the original cat on it, since the Jeep only has just over 66K miles on it. I'll have to put that on my list of "to-dos" once I get it running again.

Again, thanks for your help on this. I'd still be spinning my wheels on my problems without your help.

[bmorgil]

You are welcome test! I wont say who did the work but, many early emission control modifications have been seen by these eyes.

You have a way out, and I have used it in other states several times, that allow the "Cost to Repair Waver." Take or tow it to a shop highly qualified in expert emission control repair. Get an estimate to replace the 50,000 mile plus cat and completely restore the system to original (that will require an original carb). That total should be several thousand dollars. Take the estimate with the vehicle as is, to the test or registration center. You should easily get a waiver. In your state $715 is the magic number. The cost of repair will exceed the value of the vehicle in most cases, which will fall under "Hardship Laws" if you wish to sue for it! You might even win and beat out the government.

Way back when this "idea" to test vehicles was launched, many U.S citizens, shops, organizations and O.E.M.'s myself included, wrote our state congressmen to remind them of two things. The fact that older vehicles being targeted, had a life span and that those older vehicles had greatly reduced numbers and were not significantly adding to pollution. The real one that got the EPA to understand was the cost. Not everyone who drives an older vehicle can afford the astronomical cost to repair a vehicle that had lost most of its value. Thus there are waivers in almost every state. They just don't come out and tell you! The next thing the EPA did was mandate that 0.E's covered pollution control devices for 50,000 miles. All O.E's used stainless to combat this. Unfortunately they left from the cat back non-stainless for a while. Consequently the exhaust fell out on the highway in short order because a cat emits acid when water vapor is present. You can see the cost of vehicles beginning to climb from that point on as serious technology is needed to do it the right way.

I should tell you a story about a 1977 GM truck with a cammed up stroker motor. A 450hp high torque truck engine polluter. The local expert wanted an exuberant amount to find and reinstall all the factory pollution control equipment and a new single 2"cat exhaust (inducing exhaust manifolds, no headers) and a new cat. As we joked about it, we had to wonder if we put that si@ on it, would it even run? The hand ported aluminum after market heads from my shop weren't allowed either.

https://leg.colorado.gov/content/emissions

[test1328]

Hey Bob, I'm hoping you can help me on this a bit more. As an update, I removed the carburetor and completely cleaned and rebuilt it. I put it back on the vehicle and primed the carb and the Jeep started right up and ran well. I had to dig my old dwell meter out with the tach so I could set the idle speeds, but overall, it seems to be running quite well. The automatic choke seems to be set correctly so it works very well, opening up slowly as the vehicle warms up. I also seem to have solved the issue of the the engine dying when you come to a stop until it gets really warm. Here is the issue: Before the carb rebuild, the Jeep was always difficult to start when cold. I would have to pump the accelerator many, many times and crank the starter for upwards of 30-40 seconds (multiple starting tries, not continuously). Now, after the carb rebuild, I'm having this same issue. I'm starting to think that perhaps my fuel pump is crapping out on me. Prior to the carb rebuild, when I removed the fuel line from the carb, I was getting a strong gas stream when cranking the engine, although I didn't measure the pressure. Any ideas here? Does it sound like a fuel pump? Once I get the engine started, I have no issues keeping it running and if I shut it off, it will start right back up. So...I question if it really is a fuel pump issue. It seems very odd to me. I do think I need to pay a bit more attention to the choke setting and that perhaps it is keeping the butterfly valve on top of the carb too tightly closed when first starting it, so it isn't getting enough air and perhaps is choking it out so much that it won't start? What do you think? But then when I prime the carb and put gas directly into it, it starts with no issues.