Sputtering Past Idle

Hi All, I have done a search and have learned some but have a specific 'sputtering' problem. 1966 4 134 engine. Starts with little to no choke in 70 degree weather. Sometimes in conks out. So when it stalls I restart and it runs good at idle. BUT it bucks and stalls whenever I give it any gas. Open gas cap, no vacuum. No bubbles in glass dome. Should I try starter fluid in the carb to test fuel while someone else presses on accelerator? I was hoping these symptoms sound familiar to you guys far more experienced than me and maybe help narrow the cause. Thanks for reading all this and for the input! Cheers.

 

What kind of carb do you have?

 

You shouldn't need a parter to operate the gas pedal, you can just operate the lever on the carb itself.

 

accelerator pump.
With the engine off, operate the throttle with the aircleaner/tube removed and watch to see if you get a stream of fuel down just above the butterfly valve.
Could just be small crap in the float bowl clogging the pump inlet at the bottom of the bowl.
Running SeaFoam through your fuel system may take care of it.

 

Hey Guys, oh man lots to think about. So the Carb is super clean as of last October, stock from 1966. This just started a week ago. Otherwise ran perfect every turn of the key.
Rotor button? Man I don't know what that is! The jeep is garaged so should all be very dry. I am stuck at work but will check the throttle with engine off. Glenn, I dont know what a good condenser or coil even looks like. The jeep is new to me for about a year and things 'look' clean and solid but I am am sure the last owner didnt spare no expense to keep her running!

 

Also my first thought. The acceleraor pump is intended to prevent the engine stumbling as it comes off idle.

Does yours run smooth if you can get it past the stumble? Then suspect the pump. Maybe the diaphragm is at the end of it's service life.

 

Hey Pete, Good question. It actually sputters more. Jeep bucks will driving in first with just a little bit of acceleration. Too much gas and it stalls. Was easy getting down the hill.
Barely made it back up. So to answer your question. When in gear the more gas the more stumble, get really get past it.

 

I checked inside the carb while operating the throttle. I do see gas but it is not a constant stream more of a dribble.

 

Then maybe more likely a generally lean condition, possibly water/crud in the float chamber, or a vacuum leak?

Also, possibly points are oxidized or need gap setting.

 

Sudden onset of problems is usually electrical in nature. Do you have a Vacuum Gauge and a Dwell/Tachometer? What is the model of the carburetor?

 

Nope on the water. Believe it or not I convinced my wife to leave her car out so I can keep mine in the garage! I done have a tach or vacuum gauge. The carb is a "Carter YF'?
How can I check for vacuum? I will check under distributor cap shortly.

 

Inside of the distributor cap look clean and dry. Should I try cleaning of the connections with some steel wool? They look a little tarnished. I will also pick up a can of SeaFoam too.
Some antifreeze did leak out of the thermometer housing when I drilled my 1/8" hole a couple weeks back but really not much else in terms of water/dampness. Thanks again guys!

 

Vacuum test gauges are really inexpensive. Hook it into the port on the side of the head just beneath the carb. Disconnect the PCV line there during the test.

Also look for loose connections, cracked vacuum lines. A can of starting ether (or a propane wand) sprayed around the carb base gasket should not cause any change in the idle. If you have the vacuum-pump/fuel-pump, the diaphragm may be suspect.

Points need to be .020" and clean. Very fine sandpaper, then also swipe a business card though them. Bad points can give exactly the symptoms you describe.

 

ok great! Off to work on the points. I just watched you tube on how to check check point gap. Which is actually snug on mine. Do I just sandpaper the contact 'point' of the points?
Dumb question seems obvious but don't want to miss anything. Will keep you all posted and thanks for the helpful leads!!

 

Hi All, checked the points with slip gauge and picked up a can of SeaFoam. It worked!!! until the next thing haha. Thanks so much for the help. Should I do the seafoam again during my next tank full? I will probably replace some of the older distributor components in the near future. What else do you guys typically do for general mechanical maintenance?
cleaning etc.? Huge help, cheers