Ok I have 6 turns in my vacuum advance. The base timing 10-11. I have it set to 36 at 2500rpms full vacuum advance. The car will not idle below 1150 or 1200 and it is very hard because the idle changes especially when the electric fan turns on it loweres the car to a die if I am not base idling at 1200. The car will dip and not recover unless I hit the gas. Then after all that it will diseal at shut down but it is running 200-215 in temp maybe that is causing it. I have changed the jetting to 71 in front and 78 rear which I think I'm going to bring them down it smokes to much when I get on it. I don't understand why this car won't hold a good idle 900-1000 or so. With the idle screws set at the best vacuum I get around 10 or 11 inches. This is a 406sb, 292 244@ 50 cam with 530 lift int/exh. I have afr 195 heads and a 750 holley dbl pumper with a 4sp tranny. Help this is really frustrating.

With full vauum advance you should have close to 50* timing,what kind of distributor? how much mechanical advance in the distributor? You need to get the timing right without vacuum advance.

accel hei. We have the lighest spring and fly weights.

My motor is similar to yours, except my advirtised is 302* with the same 244* at .050. Mine idles at 850-900 in gear with 16* initial plus 4* with manifold vacuum. First and formost you need to remove your carb. I've been through this many times.

Carb: Remove and adjust throttle blades until the proper amount of the transfer slot is showing. Do this for both the primary and secondary blades. Reinstall.

Distributor: Install medium springs or send it out to be recurved. Your curve MUST start at 1500RPM or so, NOT 1000RPM.

Set base timing to 16-18*. 10-11* is not nearly enough for that cam. Vacuum advance is an option, and I find it works best if you have an adjustable vacuum canister. Check floats, adjust idle speed, check vacuum leaks, adjust mixture, re-adjust idle speed.

Silver 69 brings up excellent points. If that doesnt work check your valves.

Originally posted by faulkkev:
Ok I have 6 turns in my vacuum advance. The base timing 10-11. I have it set to 36 at 2500rpms full vacuum advance. The car will not idle below 1150 or 1200 and it is very hard because the idle changes especially when the electric fan turns on it loweres the car to a die if I am not base idling at 1200. The car will dip and not recover unless I hit the gas. Then after all that it will diseal at shut down but it is running 200-215 in temp maybe that is causing it. I have changed the jetting to 71 in front and 78 rear which I think I'm going to bring them down it smokes to much when I get on it. I don't understand why this car won't hold a good idle 900-1000 or so. With the idle screws set at the best vacuum I get around 10 or 11 inches. This is a 406sb, 292 244@ 50 cam with 530 lift int/exh. I have afr 195 heads and a 750 holley dbl pumper with a 4sp tranny. Help this is really frustrating. Rapid Robert said it.You shoud have 36 total w/out the vaccum advance connected,about 48-50 with it connected.

36-11= 25 of vaccum advance, RIGHT?? So adjust your springs to get about 12-14 mechanical advance(springs), to give you the 48-50 total.

But, I like to run as much initial as I can,lightest springs,and least amount of vaccum advance to get all 36 in by 2500rpm with Vaccum Advance disconnected.

Wichever way your combo runs best.Initial+Mechanical+Vaccum Advance

Just one more thing to think about, and I beleive this is what my problem was. "BAD GAS". I put some fresh stuff in a now mine Idles. If it's cold it needs a little feathering but once warm no more problems.

Originally posted by BLT4FN:
Just one more thing to think about, and I beleive this is what my problem was. "BAD GAS". I put some fresh stuff in a now mine Idles. If it's cold it needs a little feathering but once warm no more problems. I waited an hour for gas fresh out of the tanker today. I was bored ok. graemlins/clonk.gif