Phantom fluttering

[custom10nut]

Originally Posted by geezer#99

And one time more and only one time more, what is your timing set at?

I'd have to check for sure, but if I remember right it's at the factory setting(4 degrees BTDC?).

[custom10nut]

Originally Posted by custom10nut

I call it flutter because I don't know how else to describe it. The tach doesn't move while its doing it. The timing is set where I've always had it, and all the vacuum lines are fairly new. With all the input on here I'm beginning to think it may be trans related.

Originally Posted by 1969c10joe

and when you gas it your vacuum drops below 10 in vacuum power valve stages into rich mode and the symptom disappears?

Yes it is gone until I start cruising again. Another thing I noticed today is that it happens at lower cruise speeds also. It seems to happen whenever the throttle is held at a steady speed.

[geezer#99]

Bump your timing to 14 initial and I'd bet your 'fluttering' goes away.

[1969c10joe]

yes geezer is right more timing advance will really wake that engine up mr geezer sir would the advanced timing help burn a lean mix more completely?

[1969c10joe]

I was onthe phone with edelbrock (the co not the man)tech guy said the 1406 is calibrated for fuel economy it does not run well at sea level we both live close to sea level i think yes that was a long time ago but my memory isnt that bad (i hope)

[1969c10joe]

due to my limited experience compared to geezer and the fact that i dont know your ignition timing I would start at a lower number.I also holed a piston once on sweet smooth running sbc. sae certified mechanic timed it never again

[Jrainman]

Originally Posted by custom10nut

Yes it is gone until I start cruising again. Another thing I noticed today is that it happens at lower cruise speeds also. It seems to happen whenever the throttle is held at a steady speed.

Ok so I have experienced this a few times , and you are describing it fairly well as a flutter , at steady speeds , I have a question though, when you go up a road that has a increased up hill grade at a steady speed does the flutter seem more pronounced or less felt as you drive up a road that has a up hill grade.

[1969c10joe]

In the mid eighties i worked in a motorcycle dealership due to epa the bikes ran lean they would say it was hunting surging running out of gas i think fluttering would describe it. It only shows up in cruise mode just trying to help good luck

[1969c10joe]

when i was a clueless kid now im a clueless old guy geezer is nodding his head took my charger to a shop the old mechanic said it was dithering. it was my vac advance.

[custom10nut]

Originally Posted by geezer#99

Bump your timing to 14 initial and I'd bet your 'fluttering' goes away.

I'm away from home right now, but when I get home I'll adjust the timing.
So you're saying 14 deg BTDC, right? It's been a long time since I last checked my timing, so this quite possibly is the problem. Hope

[1969c10joe]

I humbly suggest setting timing first its always a good idea to make one change at a time

[geezer#99]

Originally Posted by custom10nut

I'm away from home right now, but when I get home I'll adjust the timing.
So you're saying 14 deg BTDC, right? It's been a long time since I last checked my timing, so this quite possibly is the problem. Hope

Yupper!!
Be conservative if you like. Better to err on the low side. Try 10 to start. Bump it a to 12 if it starts nice. Your idle will increase a bit. Just turn it back down on the curb idle screw. And you'll likely need to adjust your mixture screws a bit too.
Don't forget to plug off the vac advance hose to the vac pot when you adjust your timing.

[1969c10joe]

right on geezer where should he plug his vacuum line? full manifold ?he asked about it earlier. when he hits the gas hes gonna love it!