My Willys 3A and 3B Community
3A, 3B, DJ Technical Knowledge Base => "Original"-- Technical Questions, Answers, Observations => Topic started by: specialty on January 03, 2016, 04:20:10 PM
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Finally got my 3A fired up after it has been idle for 20 or so years. I rebuilt the carb, but it just won't run for more than a few minutes. I am happy with the way it sounds while running, no smoke but burning gas no knocking or banging. I have the tub off redoing it but I did hook the oil pressure gauge up and it's showing about 50 lbs on cold 15-40 Rotella oil. At first it would only run a few seconds until I dismantled and cleaned the PCV components. I have taken the carb apart a few times checking my assembly and ir appears to be good. Would the metering rod cause this if it's not set just right? I have a homemade gauge 2.761 in length but not sure about it being right. Does the metering rod rest on the bottom of the jet during Idle or is it up some off the seat? The accelerator pump pumps fuel okay it seems but the engine will just sputter and pop when working the throttle then die. Also seems by the smell of gas that it may be running rich. I have to pump it a few times to restart it though so that could explain that. I did see a spark jump over at the transmission around the clutch linkage so I ran a ground and tightened the ground cable on the frame at the battery. Battery was getting discharged so I didn't get to try it since then but I don't think that's the problem. I don't have a vacuum gauge but when I put my hand on the carb it seems to have a good amount of vacuum and will shut off immediately. Could it be the metering rod causing this? Wouldn't it run if it were aleast set close to spec? Any help or ideas? Thanks :-X
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Forgot to add I also installed a 12 volt system but it seems to work fine. Oil light on with switch and goes off when it runs.
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Make sure your your rubber fuel lines, if any (usually running from the fuel pump to the fender mounted hard line) are not kinked or restricted in any way. At one point I thought I had a carb issue only to later realize a twisted fuel line was allowing enough fuel to pass through in order to start but not run at high RPM's for very long.
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The metering rod won�t generally cause a cut out after running for a short time.� When properly set, it hovers a tiny amount above the seat during idle.
-The float and the float needle can cause this issue if it�s not set, or not working correctly.
-A dirty gas tank will have the symptoms you describe.� Under vacuum, debris in the tank will get sucked up by the pickup tube� stopping the flow of gas.� Once the engine stop and the vacuum is gone, the debris releases and floats away.� On the next start, the vacuum returns, sucks the debris back in to the pickup tube�and starts the cycle all over again.
-Ryan mentions, kinked fuel lines.� Also, worn out rubber lines can pinch off the fuel source.� If worn out, they contract under vacuum, effectively cutting off the fuel supply. This is one reason that there was only a short rubber piece in the original fuel line set.
Tim
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Actually the metering rod sits on the jet to close off the fuel going to the main jets during idle. That allows the fuel to go to the idle system alone. As you open the throttle the throttle plate opens air passing� the idle port above the plate when it's closed and as the throttle is opened farther the metering rod lifts off the jet and allows fuel to go through the main jets in the venturi jet.
I think the lever that lifts the metering rod has .040" clearance before the metering rod lifts off the jet in the bottom of the fuel bowl. Years ago I did an extensive test of metering rod tools and how to adjust the metering rod. It may still be available here.
If you open the throttle does the engine still die after a few seconds?
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Finally got my 3A fired up after it has been idle for 20 or so years. I rebuilt the carb, but it just won�t run for more than a few minutes. (Did you clean it thoroughly and then blow all passages out with clean, dry air?I am happy with the way it sounds while running, no smoke but burning gas no knocking or banging�. At first it would only run a few seconds until I dismantled and cleaned the PCV components. I have taken the carb apart a few times checking my assembly and ir appears to be good. Would the metering rod cause this if it's not set just right? I have a homemade gauge 2.761This gauge needs to be 2.781� in length but not sure about it being right. Does the metering rod rest on the bottom of the jet during Idle or is it up some off the seat? The accelerator pump pumps fuel okay it seems but the engine will just sputter and pop when working the throttle then die.Sounds like timing to me. Also seems by the smell of gas that it may be running rich.Is the throttle shaft loose in the throttle bores? Are you using choke just to get it to idle? I have to pump it a few times to restart it though so that could explain that.(Sorry, no it only means you need more fuel than normal to start it. I did see a spark jump over at the transmission around the clutch linkage so I ran a ground and tightened the ground cable on the frame at the battery. Battery was getting discharged so I didn't get to try it since then but I don't think that's the problem. I don�t have a vacuum gauge(Along with a Dwell/Tachometer, both are essential tools.) but when I put my hand on the carb it seems to have a good amount of vacuum and will shut off immediately. That doesn�t help the carb.)Could it be the metering rod causing this? Wouldn't it run if it were aleast set close to spec? Any help or ideas? Thanks :-X
Did you change out the condenser and points? Is your timing correct? Have you checked the distributor for excessive wear in the shaft bushing? For more information and answers to your questions visit my website, www.oldjeepcarbs.com
It�s a free reference library with no obligation whatsoever.
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Per Carl... "Actually the metering rod sits on the jet to close off the fuel going to the main jets during idle. That allows the fuel to go to the idle system alone."
Clearly Scoutpilot and Carl know more about the Carter WO than I do...so...for my own clarification...
You set the metering rod with the idle adjustment turn all the way out/off.
Once the metering rod is set, you would then adjust the idle screw.
Wouldn't this idle adjustment slightly raise the metering rod off the seat?
Tim
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[size=12]A little nomenclature is required here.
A. The Steel Idle Stop Screw is primarily for adjusting the flow of air past the idle port in the throttle. It is adjusted to achieve the highest vacuum possible at idle.
B. The Brass Idle Mixture Screw controls the amount of fuel (rich/lean) that flows into the throttle.
With Idle Stop Screw backed out so it is not touching the throttle body when the butterfly is completely closed, set the Accelerator Pump stroke (17/64�) and then the Metering Rod height (2.718�. Sorry my previous post is slightly dyslexic) is set. The tip of the metering rod is bottomed in the jet. It only raises when the throttle is actuated. This setting is critical in that if the rod does not simultaneously raise when the accelerator pump begins its down stroke, the fuel flow will be interrupted and the motor will stumble. After these two settings have been accomplished then the Steel Idle Stop Screw is turned in only enough to expose a portion of the idle port often referred to as �The Perfect Square� in that the vertical opening is the same as the horizontal width. The properly set Metering Rod will not raise when this setting is applied.[/size][/b]
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Actually the metering rod sits on the jet to close off the fuel going to the main jets during idle. That allows the fuel to go to the idle system alone. As you open the throttle the throttle plate opens air passing� the idle port above the plate when it's closed and as the throttle is opened farther the metering rod lifts off the jet and allows fuel to go through the main jets in the venturi jet.
I think the lever that lifts the metering rod has .040" clearance before the metering rod lifts off the jet in the bottom of the fuel bowl. Years ago I did an extensive test of metering rod tools and how to adjust the metering rod. It may still be available here.
If you open the throttle does the engine still die after a few seconds?
The engine will sputter and die. I have read your test om the metering rod. Plan on doing that today. Thanks
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[size=12]A little nomenclature is required here.
A. The Steel Idle Stop Screw is primarily for adjusting the flow of air past the idle port in the throttle. It is adjusted to achieve the highest vacuum possible at idle.
B. The Brass Idle Mixture Screw controls the amount of fuel (rich/lean) that flows into the throttle.
With Idle Stop Screw backed out so it is not touching the throttle body when the butterfly is completely closed, set the Accelerator Pump stroke (17/64�) and then the Metering Rod height (2.718�. Sorry my previous post is slightly dyslexic) is set. The tip of the metering rod is bottomed in the jet. It only raises when the throttle is actuated. This setting is critical in that if the rod does not simultaneously raise when the accelerator pump begins its down stroke, the fuel flow will be interrupted and the motor will stumble. After these two settings have been accomplished then the Steel Idle Stop Screw is turned in only enough to expose a portion of the idle port often referred to as �The Perfect Square� in that the vertical opening is the same as the horizontal width. The properly set Metering Rod will not raise when this setting is applied.[/size][/b]
I went to your page over the weekend. Monday after noticing all my linkages were sloppy I noticed the free play in the shaft. Following your instructions I tore it back apart put it in the milling machine doing precisely what you recommended step by step and the results were perfect. No more shaft play and linkage is tightened up quite a bit feeling like it's not ready to fall off anymore. Next step is to set the metering rod. From all the drawings I see they recommend the gauge at 2.761 but you say 2.718 so that's the length I will make the gauge.
Parts are hard to find here so with my 12 volt conversion could my 6 volt points and condensor also be breaking down? I have them ordered bit would any condenser that's 12 volt work? Surely other vehicles used the same points back in 1952 that I could get locally. Hate waiting for parts! Anyway going to check the timing and do the points and condensor and see if my carburetor rebuild is doing it's job since the throttle shaft and metering rod will be good.
Thanks to all. If this works I will let you all know, if not I will be back!
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[size=12]I�m pleased you found some success. Be sure and check out the videos there for setting your float, metering rod, etc. However, it is not a good long-term plan to mix twelve volt and 6 volt. Rule of thumb on a 12V conversion? Change everything, if you can afford it, or change nothing. For the correct part numbers check out this list. http://www.thecj2apage.com/NAPA.pdf
The part numbers may have changed but any decent counter guy, or gal, can cross reference. Don�t let them get away with just looking on the computer if they can�t find it. ALL shops have the books.[/size][/b]
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Scoutpilot, Thanks for the parts list. I will print that off and put it in my folder for now and future reference. Actually since I don't have the tub on the chassis right now the only things not 12volt are the condenser and the starter. Could the condenser since it is on 12 volt system be causing my issues? I know I have read and have had old Chevy trucks that ran the starter for years with no problem. But what about the ignition? I did install a 12 volt coil with a external ballast since the one I bought said it required one. Would it mess up the condenser right off the bat and cause this? I did use a 3 wire setup so I wouldn't have to deal with the single wire charging issues. Thanks
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[size=12]It is more like that the condenser was on its way out when you bought the Jeep. Replace it with the correct unit listed. But purchase two or three as the likelihood of failure in modern production equipment straight out of the box is high. The condenser doesn�t really care what the voltage is.[/size][/b]
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[size=12]It is more like that the condenser was on its way out when you bought the Jeep. Replace it with the correct unit listed. But purchase two or three as the likelihood of failure in modern production equipment straight out of the box is high. The condenser doesn�t really care what the voltage is.[/size][/b]
Now I want to try to set the timing but I can't get the distributor to move. What is that round knob on the side of it that is spring loaded when it's pulled out? Loosened the clamp and tapped on it still no move. Also My bellhousing cover has no hole any where to set it. Can't see any marks on the crank pulley so I was going to set it by ear until I can get a friend who is a mechanic to set it with a dwell meter or something. After all the work with bushing the carb and making the metering rod tool to 2.781 like you suggested it still only runs for a short time. I feel fairly confident the carb is right so now I am leaning to a electrical problem or timing. I also thi nk the oil pump at one time was put in 180 degrees off because the plug wires are opposite of what they should be.
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update. Went back a hour after sending you the last post and turned the key and it ran! Ran I would say about 2000 to 2300 RPM nice and smooth with nothing but an occasional puff. I had the linkage for the idle screw on wrong so I cut it off and put it where it should be so I could idle it down. It runs much longer than it did before but it stutters and eventually cuts off. Like it maybe some sort of intermittent problem. I know now that it will run and run well just got to figure out why it runs so erratically. Checked my wire connections making sure my temporary wire job was tight and will do like you said with new condenser tomorrow. Still have not gotten the distributor to move yet or figured out what that spring loaded knob is on the side of it for. But I am seeing light at the end of the tunnel. Hopefully!
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The spring loaded knob is a oiler. You can dribble a drop of oil in there every 1000 miles or so.
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The spring loaded knob is a oiler. You can dribble a drop of oil in there every 1000 miles or so.
Not to sound stupid but what does it oil? Thanks
Trying to educate myself on these CJ3A's so I searched it and saw what it does. Right now my distributor is frozen hard so I need to get it freed up.
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Make sure your your rubber fuel lines, if any (usually running from the fuel pump to the fender mounted hard line) are not kinked or restricted in any way. At one point I thought I had a carb issue only to later realize a twisted fuel line was allowing enough fuel to pass through in order to start but not run at high RPM's for very long.
right now tub is off and running out of a 5 gallon can. thanks
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[size=12]
I had the linkage for the idle screw on wrong so I cut it off and put it where it should be so I could idle it down.
Now I�m concerned. Please post a photo of this area?[/size][/font][/b]
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[size=12]I didn't actually cut anything off the linkage, I cut off the engine. Should have made myself clearer on that, sorry. I had the linkage for the idle screw on wrong so I cut it off and put it where it should be so I could idle it down.
Now I�m concerned. Please post a photo of this area?[/size][/font][/b]
What I did was I had the tang on the wrong side of where the small screw goes in. It has 3 positions to put this little screw in and having the tang on the wrong side of the screw made the idle screw� to far away from the stop to do any good. Got that corrected now and that part is now fine. Now I need to get my distributor freed up and from my research that may take awhile. You know of any quick tricks to get it� freed up? I wanted to check timing and make sure the bushings were okay thinking that they may be possibly worn and causing my issues. That along with the timing being off enough to cause my problems. I am just trying to go through a process of elimination on things I can do myself and need to be checked anyway. I have a friend coming over who has the gauges and know how to check the other things you suggested but getting him on the ball is another subject. Going to work on that frozen distributor some today so when he does show up I am ready. I am persistent.
Any advice would be appreciated. Thanks
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The ignition timing may very well be off, but if it was off enough to cause the engine to not run it would be off ALL the time, and the engine would not run at all. The timing can not be "close enough" for the engine to run, then change after a minute or two, and cause the engine to die.
Check the things that have been suggested:
Fuel delivery- "drawing out of a five-gallon can" or words to that effect - A clean can? Drawing from the bottom, or siphoning over the top? You must be using a piece of hose, is it connected to steel line or hose-barbs anywhere, and is it air-tight? Is the hose large enough, and not kinked or twisted, etc?
Condenser - it can be tested, but no one has the equipment to test one anymore, so the only test is to substitute a known good one. And a new one may not be good. Great, huh? This has been a big problem lately. If you have another vehicle with a condenser, or know someone who does, maybe you can borrow one. A good, "wrong" condenser will be better than a "right", bad one.
Coil? again, about the only way to test is to substitute a known good one, or you could check for spark immediately after the engine shuts down. Ballast resistor - Could expand with heat and open a poor connection. See if it still passes current after shut-down.
Don't worry about timing now. It's OK part of the time, it's OK all the time. Get this thing to run continuously, then check the timing. BW
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� The ignition timing may very well be off, but if it was off enough to cause the engine to not run it would be off ALL the time, and the engine would not run at all. The timing can not be "close enough" for the engine to run, then change after a minute or two, and cause the engine to die.
� Check the things that have been suggested:
� Fuel delivery- "drawing out of a five-gallon can" or words to that effect - A clean can? Drawing from the bottom, or siphoning over the top? You must be using a piece of hose, is it connected to steel line or hose-barbs anywhere, and is it air-tight? Is the hose large enough, and not kinked or twisted, etc?
� Condenser - it can be tested, but no one has the equipment to test one anymore, so the only test is to substitute a known good one. And a new one may not be good. Great, huh? This has been a big problem lately. If you have another vehicle with a condenser, or know someone who does, maybe you can borrow one. A good, "wrong" condenser will be better than a "right", bad one.
� Coil? again, about the only way to test is to substitute a known good one, or you could check for spark immediately after the engine shuts down. Ballast resistor - Could expand with heat and open a poor connection. See if it still passes current after shut-down.
� Don't worry about timing now. It's OK part of the time, it's OK all the time. Get this thing to run continuously, then check the timing.� �BW
Actually I am running a vacuum hose to the can making sure it is submerged. I rebuilt the distributor today with new bushings and freed up the centrifugal advance. You are right, the timing wasn't the issue. When I first cranked it it ran fairly good so I thought I had it solved. after running for a few minutes it was back to running erratically again. Much better with new bushings but not right. I recently had bought another 12 volt coil not realizing it needed a external resister. I added a ballast resister from the parts store. could it be the coil is not matched with the resistor and after running a while breaking down and causing my problem? It's like it running out of gas. When I go to rev it it wants to sputter and die unless I work the throttle real fast giving it lots of fuel while it's sputters and shakes. Should I just get a internal 12 volt resistor coil with original 3A points and condenser so it;s all matched up?
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Finally got it fixed. This morning I went and got a new coil with a internal resistor and a new condensor and points in case these were fried. Also got new fuel line from pump to carb with a see thru filter so I could see it pump. I also ran a 3/8 new rubber line to the gas can. I runs like a sewing machine now. After thinking about it last night I noticed it ran better when cold and acted up after running a few minutes which from messing with newer cars told me something electrical was breaking down once it got warm. I am not sure which one of these fixes actually fixed it but I think it was the coil with the external ballast resistor causing the problem. From what I understand these need to be matched up for proper operation. Not knowing the ohms of the coil or the resister since they came from a national parts store I had no idea what they were.
I really want to thank all of you guys for helping me and each of you helped a lot. Special thanks to Scoutpilot for his patience with a rookie like myself and his input. He is surely one of the best on this subject. God bless you all! Really great people.
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Glad to see you have the problem fixed and I hope it stays this way.
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Thanks Carl.