Intermittent "puff Puff" At Exhaust

F-134? You mean the accelerator pump diaphragm?

 

Went through the carb last weekend but will do it again. Will also adjust the idle a bit more - not sure what the rpms are at idle but sounds the same, or only slight faster, as my Nissan Frontier idling at 600.

 

I vote idle it down, around 400 for setting carb, then play with air screw.

 

thanks all - lots to ponder and explore

Glenn - not 100% sure what to do about the timing. Using the proper firing order, my #1 plug wire coming out of the distributor is currently between the 5 & 6 o'clock position. I could re-install the breaker plate/points and see if I can get to 5 BTDC and then re-install the Pertronix kit BUT, in retrospect, I'm not sure that i made that much of an adjustment when I installed the kit to begin with.

I'm going to examine the pulley again and see if there's more than one timing mark/notch. Perhaps a previous owner or mechanic made one or accidentally dinged the pulley making what looks like a mark and I missed it and marked the wrong one with chalk yesterday.

Is it possible that a PO got into the oil pump and the gear is is "off" a couple teeth?

 

My Jeep has wanted to do this same thing ever since I got it and I've just learned to live with it as it has never had a effect on performance.

Assuming all the valves are in good shape, you may have the combination of a rich mixture and an exhaust leak somewhere before the muffler (possibly even a pinhole in the muffler). Just another thing to take a look at.

 

Definitely could be something with the exhaust as well. I haven’t given that too much attention. A PO clamped a muffler of some sort (may be a proper one, may not) onto the original long pipe so everything from there back is kinda cobbled together. Been looking at re-doing everything from the manifold back but funds have been diverted elsewhere. I’ll snoop around the exhaust this week in addition to the carb and idle.

At the end of the day I don’t have power loss or hesitation so at least I can drive around ok.

 

Mine is the same way and has been for the past 20k miles. I assume that I am making adjustments for compensate for worn valve guides but am unmotivated to fix it.

 

I had to mess with my dizzy clamp to get it so I could get 12-14BTDC range. Took some trial and error. Running bout 10btdc now. My carb is sensitive, 1/4 turn and idle stumbles!
Set all else first, warm engine, adj screw for high idle .

 

My CJ2A's f-head did the same thing. never could sort it out and it ran like a sewing machine for 2 years that I owned it.

 

yeah...I got the idle down a bit and adjusted the fuel/air mix and the "puff puff" has all but disappeared. She's running great, though I haven't been able to take it out for too long lately.