Carb Dash Pot Purpose?

What is the purpose of the carb dash pot on the V6? I know it slows the throttle closing but why is it necessary?

 

to gradually and slowly return the engine to curb idle speed, rather than abrubtly slapping closed, which could cause the engine to stall (dieseling,flooding?)

" The dash pot should delay or cushion closing action for two seconds by saying, "One thousand and one, one thousand and two.""

"As a final check, open carb and allow throttle to snap closed. Time dashpot delay delaying action from the point where the throttle lever hits the dash pot to the point where the lever stops moving."

 

it's the only part on a Jeep where the critical adjustment of said part is made by chanting "one thousand and one, one thousand and two"
most folks use other words when working on their Jeeps.......

 

Chanting...I like chanting. Thing is, people misinterpret it. Really, folks...I'm not about to launch this wrench into orbit...


Oh yeah...thanks for the insight on the dash pot...I've seen mentions of it, but never gave it any thought.

 

Yep, mine is delayed about that much. Irritating in a way but now that I know, necessary.

 

OK, where might we purchase a new/used dashpot ? I checked Krage's and Walck's, but did not see them on their sites. Might NAPA have them ?

 

Ok interesting question... my Holly 4bbl doesn't have one and neather does the YF on the jeep, so whats different in the designs that their not needed on these and newer carbs?

 

huh? mine dont have one...... maybe i will get one...or maybe not

 

I don't have one on my carb but have been having a problem with it stalling due to flooding when I start bouncing through the rock. Major on and off the throttle as the wheels climb up and over.
I think I'd like to try the dash pot, do they come with the mounting bracket?

 

Hmm. I could be wrong, but this is what I was told.

The anti-dieseling solenoid on Wagoneers and such (possibly also on CJs) is energized when the ignition is on, and provides the throttle setting at idle (thus the other name, idle stop solenoid). When the ignition is shut off, the idle stop withdraws and closes the throttle completely, preventing run-on (dieseling). This is not a dashpot, though I suppose some could also act like a dashpot, but it would be a functionality in addition to acting as an idle stop. Pretty sure I've seen this in situ.

I've been told that the simple dashpot prevents exhaust popping (backfire). Backfire is caused by unburned fuel igniting in the hot exhaust system. Supposedly closing the throttle rapidly boosts the vacuum suddenly, which momentarily richens the mixture and causes popping. Note I've never seen this in a book or anything - that's just what I've been told.

 

Which carb, the Rochester? Sounds more like a Holley...

No, the bracket is a junkyard item AFAIK.

 

Well I'm not sure what my Jeep is doing in the rough but when I have to chop the throttle quickly it does sometimes stall and when it restarts it coughs up a cloud of black smoke (fuel?) I'm still trying to sort out its trail manners and with 16 forward gears I need to get better at figuring out how to go smoothly over rocks without pumping the throttle.

 

Have you guy's considered that these "dash pot's" seem to be an early attempt at fuel economy.
With a good setting for curb idle on my diplomat and jeep I can rev the engine high and let go, then the engine will fall to idle.
I could be wrong but it sound like the curb idle mixture and rpm setting might be off.
ANY engine should be able to go from full rpm's to idle without stalling, and vice versa.

In my opinion

 

FYI: Here is what the V6 dashpot looks like on my 1971. This one softens the throttle return to the idle position for whatever reason. There is no electrical connection to this dashpot.

 

A couple of reasons they were used. One is what Tim said, to keep the fuel from building up in the exhaust and igniting. The big reason is emissions though for the same reasons Tim said. When the throttle closes suddenly there is a momentary supply of fuel that is only partially burned (rich condition). This increases hydrocarbons out the tail pipe. It was another effort to reduce emissions back in the late '60's and into the '70's. Nickmil

 

Originallly on the Commando, the dashpot was only used on automatics.
My 1968 stick shift did not have the feature, but the 1970 and 1971 did.
The only purpose I could see for it was to prevent run-on when shutting down the motor, which was quite the problem at the time. I believe idea was to close the throttle slowly.
The dash pot did not seem to do much of anything to help. The real fix at the time was to get an idle-stop solenoid from a GM car. Take the dash pot off, throw it in the tool box, place the solenoid. Adjustment was critical.
When you shut the engine down, the solenoid snapped closed, dropped the linkage, and the engine shut off.
I probably have a few of the original dash pots.