Off idle bog

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DARTLARRY

DARTLARRY

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I have an LA 360, weiand stealth intake, with a carter 625cfm AFB. It runs great beyond 1500 RPM. It stumbles, and misses a little when leaving a light, until the RPM come up. Timing is at 14 initial, and 34 total. Any help would be appreciated.
 
any other modifications? what is your idle set at? possibly increase timing to 16 or even 18 initial and back down the idle at the carb if too high. Have you checked the primary float for proper adjustment or binding?
 
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I had similar, found vac advance was plugged off. Now stab throttle and no bogging.

Don't want to have go #2 on the merits of vac advance, just saying what I experianced.
 
There are 3 sizes of squirter for those. Last time I looked (a month ago) you couldn’t find them.

You might need to adjust the linkage to get a longer pump shot. Or, you may need the middle size squirter. I doubt you’ll need the biggest one. That thing is like a garden hose.

And as lil said above, you could use a couple degrees more initial. Just make sure you get that without adding total timing, although 36 or maybe even 37 won’t hurt on pump gas.
 
Sounds like your 2 idle fuel ports are plugging off with gum from old fuel.

Back the 2 idle fuel mixture screws all the way out, spray some carb cleaner in them a few different times, maybe even run a small parts tag wire in them to help clean them out.

Polish up the ends of the adjustable fuel mixture needle screws with a scotch brite pad and carb cleaner. Then rinse everthing out with carb cleaner and blow out the idle fuel mixture ports with compressed air.

Reinstall idle fuel mix screws 1 1/2 turn out from seated, warm the engine up good them readjust the idle mix screws to get it right.

Good Luck . . .
 
Look to see if it's getting a pump shot.
 
DARTLARRY said:
I have an LA 360, weiand stealth intake, with a carter 625cfm AFB. It runs great beyond 1500 RPM. It stumbles, and misses a little when leaving a light, until the RPM come up. Timing is at 14 initial, and 34 total. Any help would be appreciated.
Click to expand...

1500 RPM is where the primary booster begins to flow so we can narrow it down to the transfer circuit. Disconnect the pump shot lever and drive the car on just the transfer slot easing into the throttle as you do. The car should not have any drivability issues and if it does then you have a problem there and it needs to be further investigated. Never use the pump shot to cover transfer slot issues.
 
I have a small cam, it idles at 700. It sometimes has a small miss at idle too. I increased the timing to 16, no changes. I have a Holley demon carb, I switched out from the AFB, same problems, small miss at idle, and a low rpm bog under a load. I am thinking it is an ignition problem now.
 
I agree with @Hysteric , in that you are probably too far down the transfer slots.

The easy check is to do as he says, and I would increase the idle speed ~50 rpm atta time until the sag disappears, then report back.
If the idle speed goes up too high, retard the timing ~3 degrees atta time, to slow it down; for this test, do not use the speed screw to slow the idle.
 
Well then it's not he carb....

Vacuum leak
Plug gap
Wire leakage
Carbon track in cap
Rotor burn through
Check dwell if point ign.
 
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