Help on 77 cj5 carb

bmason04

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Feb 6, 2009
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morganton
So I replaced the carb on my 77 cj5 w a new carb. It didn't have this piece on it. Can't seem to find one online anywhere. Anyone help me where I can find one or tell me what it's called?
 

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This is a motorcraft carb on a 304
 
It's called a dashpot
 
That's a dashpot.

Oops, someone beat me to it.

Anyway, it acts as a damper of sorts, to slow down the throttle plate closing when you let off the throttle quickly. It's an anti-stall device. Your new carb might not need it, depending on what you got for a replacement.

Automatic trans I assume?
 
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What exactly does it do? The jeeps not running right wonder if it has to do w this not being on there
 
bmason04 said:
What exactly does it do? The jeeps not running right wonder if it has to do w this not being on there
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See my post above. I don't think it has any affect on the engine running right, as it has a very limited function. Again, your new carb may not need it.
 
See that now. Ha. Well my jeep ran good before(semi) but the new carb is the same one just a reman from guaranteed carbs. It has a notch for it but not drilled or taped. I'm not having much luck finding one. I still have my old one but I want a new one on it. The jeep will crank up and run for about a minute and then stall out. I'm thinking that is the issue.
 
I think your problem is something else. The dashpot helps prevents stalling when you suddenly release throttle. Think shock absorber. When your engine stalls determine if it lost spark or lost fuel. Fuel loss could be a dirty fuel filter or fuel pump issue. Spark problem could a component that works good cold but fails when hot
 
First, the dashpot has no effect on it "running"... It's to buffer the closing of the butterflies, so they don't slam shut when you let off abruptly. Others bump the idle up for parasitic engine loads (like AC compressor)

bmason04 said:
The jeep will crank up and run for about a minute and then stall out.
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Despite being "new" (which it likely is just a reman, since they stopped making them in the late '80s), you may still need to tune it... float level, idle, etc...
Does it run good for that minute?
What kind of filter do you have on it? Good flow thru that filter?
Have you pulled the gas cap to make sure it's isn't pulling vacuum in the tank?
Have you checked the float level? (you can pull the top off and run it without, as long as you hold the float from coming all the way up = fuel everywhere)
Jets clear? (mine would *always* find some trash, despite running 2 filters)
 
Tank, sending unit, carb, and fuel filter are new within the last 4 months, plugs and wires last fall, fuel pump about a year ago. It cuts off pretty harshly
 
The dashpot is not the cause of your stalling, even though it's called an anti stall dashpot. Like said above it works like a shock absorber, when the throttle is open a spring pushes the rod out and a chamber behind a diaphragm fills with air. When you suddenly close the throttle like a panic brake situation, the throttle hits the rod before it hits the idle speed screw, all the air in the chamber has to bleed out through a tiny pinhole so the throttle will slowly close the last 1/4 or 1/8". After 15-20 seconds of the throttle being closed the dashpot isn't doing anything. The throttle will be closed against the set screw.

If it ran with the old carb but not the new one I'd start looking at stuff that got changed. Is it still getting fuel? Does the new carb have a valve that blocks the fuel bowl vent? If so does it open?

Sent from my XT1254 using Tapatalk
 
They claim the carbs are bolt on ready. Already bench tested, flo tested ready to bolt and go...
 
bmason04 said:
They claim the carbs are bolt on ready. Already bench tested, flo tested ready to bolt and go...
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So are a lot of aftermarket carbs like quick fuel, but you still have to tune them to your engine. I've found debris inside the fuel bowl of brand new Holley carbs before. Every new carb I get gets pulled apart, blown out with air and looked over. That would go double on a reman.

If pulling the carb apart will void the warranty, you may need to send it back.

But check the fuel flow and spark first.

Sent from my XT1254 using Tapatalk
 
Once the carb was replaced it ran good a few seperate times. I drove around the neighborhood w it. Then it say for a few weeks and won't run over a minute without cutting off
 
bmason04 said:
Once the carb was replaced it ran good a few seperate times. I drove around the neighborhood w it. Then it say for a few weeks and won't run over a minute without cutting off
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Sounds like it may have gotten trash in it.

Sent from my XT1254 using Tapatalk
 
Well talked to the company, they are gonna let me send my original in, rebuild it and send it back to me. So prolly gonna do that and keep it original.
 
Check fuel pump, filters, and fuel strainer. Bet your tank has rust and took out the pump, causing bleed off and starving carb for fuel. Retro fit it with an inline electric. Bonus would be to retro fit with a recirculating fuel supply to help eliminate flooded hot restarts due to fuel vaporization. Basically a fuel pump with regulator at carb with return to the tank. IMO, best upgrade to a carb system.
 
The tank was a brand new one in the spring. Highly doubt rust there, and I've thought about a new fuel pump but the jeep has a mechanical one on it so I'm not sure how it would work if I took it off
 
To replace a mechanical with electric, simply move inlet to inlet and outlet to outlet. Wire power to pump from run position (coil power with a relay is excellent, or most times ignition system power wires have enough capacity to just piggy back the wire right to the pump. Most inline pumps only draw between 2 & 5 amps iirc) and add a fuel filter before the pump for pump life. Although I'm with you, a less than year old tank shouldn't be rusted up enough to crud up the works. On the existing mechanical pump, loop the fuel line inlet to outlet or remove the pump and install a block off plate. Only reason to cap or loop the line is to keep crap out and eliminate a weird bearing gone out noise if it still happens to pump on occasion.
 
You said it cuts off pretty abruptly. Typically fuel issues will sputter and engine out. Electrical will give an abrupt cut off.

Could you have an electrical issue that is showing its head. Maybe coincidence in timing of carb swap?
 
When motor quits when will it restart ? If it doesn't restart quickly run it till it stops, remove air cleaner, look down carb and open throttle all the way quickly, if you see a squirt of gas you have not run out of gas. If you see a squirt then remove a spark plug wire from the easiest to reach spark plug and connect a spare spark plug to the wire and lay the plug on metal part of engine, have somebody crank engine while you observe the plug for a spark. Before you change parts I would do some troubleshooting. If it restarts immediately it's probably an electrical issue such as a loose wire, shorted wire, or bad switch.
 
Cap and rotor. Had a international tractor would quit exactly 5 minutes after starting. Every five minutes of run it died. Turned out to be a bad rotor button.
 
mbalbritton said:
You said it cuts off pretty abruptly. Typically fuel issues will sputter and engine out. Electrical will give an abrupt cut off.

Could you have an electrical issue that is showing its head. Maybe coincidence in timing of carb swap?
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Well yes it sputters out. Sorry for the wrong wording
 
moldman05 said:
When motor quits when will it restart ? If it doesn't restart quickly run it till it stops, remove air cleaner, look down carb and open throttle all the way quickly, if you see a squirt of gas you have not run out of gas. If you see a squirt then remove a spark plug wire from the easiest to reach spark plug and connect a spare spark plug to the wire and lay the plug on metal part of engine, have somebody crank engine while you observe the plug for a spark. Before you change parts I would do some troubleshooting. If it restarts immediately it's probably an electrical issue such as a loose wire, shorted wire, or bad switch.
Click to expand...

It will start back pretty easy but just depends.
 
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