timing or carb issue?

[gotdust57@yahoo]

i have 73 duster 360 mild cam, i have my timing set at 34* at 2800 rpms, sometimes it idles real high when i start it about 2300 rpms,it is edlebrock 600 cfm electric choke, i can get it to idle down if i flip up lever on choke by the dial knob on electric choke side, i set my idle at 1000 rpms that about as high as i can go without it ramming into gear, at 1000 rpm idle when i stop at stop sign and in gear it will either die out sometimes or it will lunge like it is choking itself out and rpms will go up and down from 1000 rpms to about 4 or 2 hundred and sometimes die out, do i have choke or carb problem or is my timing to much? thanks

 

[crackedback]

How much of your ignition timing is initial and mechanical?

That is the key. Total is pretty insignificant from an idle adjustment standpoint. Is it done advancing at 2800. What was the reading at 3500?

If the cam has 220-230 @ .050, put at least 14* initial. This may require limiting the mechanical advance in the distributor.

Lots of carb issues are rooted in timing problems.

 

[gotdust57@yahoo]

i am not sure what my inital was, i never timed a dist before, i bought a actron digital timing light that you scroll up and down to get your number, i set digital at 34* set rpms at 2800 and turned dist counter clockwise till slot was lined up with zero and clamped down, i think the timing is my problem , can i dial it back to another setting at 2800 rpms to fix my mistake? please help with suggestions

 

[C130 Chief]

Yeah, go back 5 degrees and see if it is better.

Better yet, use your dial-back light to see how much advance you have at idle. Any more than about 12 degrees, and you may start having idle issues. Make sure your vacuum advance is connected to ported, not manifold vacuum.

 

[gotdust57@yahoo]

thanks, i will give it a try the car runs really strong at the 34* but not worth the little extra uumph

 

[C130 Chief]

Something to check with the Eddy is to make sure the metering rods are down all the way at idle.

Also, make darn sure you don't have a vacuum leak somewhere.

 

[crackedback]

You have a vacuum gauge?

If so...

Advance the timing at idle until the engine stops making more vacuum, then back it down one inch. More advance usually equals stronger vacuum signal to a point = easy carb adjustments. As long as it doesn't run on when shut down or kick back on the starter, you're on the money

I'm not a fan of limiting initial advance to some random number. Let the engine tell you what it wants. My basically stock 340 likes 16* initial. Starts fine.

Try to get out of the fascination with the total advance number. That might be the goal number, but, if it's currently 6* initial and 28* mechanical, you're giving up a bunch of low end response. 14* int. and 20* mech. would be better and likely make the carb adjustments much easier.