buick 455 running on after shut off????

The distributor was a Napa distributor and I had EveryDay Performance test it. 1111964. I think you nailed it as I have the vacuum advance hooked to the carburetor, not the manifold. The dwell is set to 30' and the timing @ 0 with vacuum line plugged. Rpm @ 800. I got to look up that distributors stats as it seems to me it was set to 38' full advance... which would make sense to set the initial timing @ 4' If I only need 34'...
I have A T&A mild cam with aluminum heads. Running 170psi respectively. Stock manifolds with 3” pipes. Car runs beautiful except getting it to Idle and that’s sometimes?
Also I have a heat riser valve as I couldn’t find a blank.

 

The distributor vac is hooked to the carb,..that's not what they mean by "manifold" vac and "ported" vac,...there are nipples on the carb that supply both types,...manifold vac is picked up from below the throttle blades and ported is picked up above

 

Sounds like so much stuff has been messed with that a complete reset may be what is needed. I would disconnect the advance, reset timing, then reinstall advance and reset idle. With a "mild" cam and only 4* initial you most likely can use manifold vac for vaccum advance. Remember as you move timing your idle will be affected and need to be moved.
You probably really need a bushing to limit the mechanical advance.

 

Yup 1111964 I found Kens info and all the info I need to get this”fine tuning done”. Now vacuum ports on the Quadra-jet carb, the one I’m using is low on the right “but” not visually below the Throttle plate. Ken said that’s the correct 1 as he rebuilt the carb too. ( and it works great).
There are only 3 vacuum ports on the stock manifold. Should I/ can I/ Do you/ tee off of the smallest 1 going to the modulator valve? I need vacuum info now...

 

It doesn't have to be visually below it,..it has a channel that picks up the vac signal from where it needs it,..why are you wanting to tee into a dedicated manifold vac source?

If your going to tee into any line I would use the one off the back of the carb that goes to the canister on the firewall provided it's an AC car

 

Good I have that 1 plugged off. Now I can check my manifold vacuum there, noT needed!
What am I l@@king for in HG?

 

It’s a T&A 290-94H cam. I’m at sea level with stock rockers and T&A stage 1 street eliminator heads.

 

Thanks guys, I went through 45 years of tribal knowledge dilemmas and this being the first car I’ve Ever built. it’s been quite a learning Curve to say the least.

 

Run vacuum advance at idle and you can close throttle and it will shut off IF the vacuum can is not blown out and just causing a vacuum leak.

 

It happens now to my 455 stage 1 after install a new carburetor, I have a little bit cam on it. as I understand from Larry and other guys, I should reach the mixture to close my throttle for same idle RPM. My initial timing is set to 10 degrees so going for more initial I guess will cause more total than I should have. I inspected the engine and the vacuum was as low as can`t hold the PCV Valve and power piston tight, I had not enough time to use vacuum gauge but PCV valve make ticking and power piston was not stable down means low vacuum to me.

 

I'm watching this thread now. Cast iron heads. 10:1. Mine diesel's as well unless I mix with 100LL av gas or 110octane racing in either case netting around 95octane. No oxygenated fuel in any case ( i know sacrilege for an Iowan) . No detonation at power with marginal octane and some diesel at shutdown. That's when I hold the brake, place in gear, and let out the clutch.

 

Did he set it up to STOCK specs? If so read Larry's quote below.

Yep. at least 18, the more initial it will take the better.

 

I tuned the carburetor for maximum vacuum, However with my street/strip camshaft it seems that vacuum won`t going higher than 11.5. Mixture was lean and I corrected it, also I closed the throttle in idle as far as vacuum gauge start to drop. Also when I shut the engine off and fast idle solenoid out primaries will close completely. but does not cure dieseling. What I found is that PCV valve won`t work with my vacuum, It ticking all the time in idle and I guess when I shut the engine it will open and send the air to the intake and I don`t know what can I do with it? Also I don`t know if changing the initial will help or not? it is set on 10 degrees and vacuum advance to the ported vacuum. I have TVS switch on the manifold that will change vacuum from ported to manifold when engine gets hot but I`m not using it now, If I do in hot engine initial will go way higher.

 

Dump the TVS switch and as I said earlier connect the vacuum advance to manifold and then turn the idle (throttle plate) down and it won't run on.

 

No, I changed to Thermoquad from a 1973 Dodge charger 400 , It is high performance and non lean model, It is way easier to inspect and tune and fits what I want. all problems solved. will go for competition series when I find a really good one.

I drain the tank today and fill it with higher octane fuel also closed throttle plate little bit more and seems that dieseling is solved, I just need a good spring for my throttle, It seems that original Quadrajet throttle spring is not suitable for Thermoquad and can not close the throttle plate when solenoid is off.

Thanks, will test it tomorrow.