Hello, I come here seeking help. This might be long, but I want to thoroughly explain what I have already done, to avoid rehashing the same things (as I have done myself for weeks now).

I have a 64 Deville that I received in non running condition.  Old fuel had seized up some valves, and just about everything had to be taken apart, cleaned, and put back together.

The car only has 25,000 miles.  Well, 25,300 as of today.

I've had a really tough time getting it to run properly.  I had the heads cleaned up, a valve job performed, and hardened exhaust valve seats installed.

Compression is excellent and uniform across all cylinders, around 190.

I rebuilt the carburetor.

I disassembled and cleaned the fuel pump.

The fuel tank and sending unit have been replaced.

Obvious tuneup parts have been replaced with new.

First problem was that I was unable to get the idle down to 480RPMs in drive.  All vacuum lines were disconnected and capped to perform testing.  At first, I did have a leaking intake manifold gasket, I corrected that.  There are NO vacuum leaks.

After that, I was able to get the idle down, but it didn't run particularly well.  I adjusted the timing and dwell.  The car falls all over itself when trying to accelerate, and stalls most times.  No power. 

I went and bought an Edelbrock 1411 750CFM carburetor, as I suspected trouble (and doubted my rebuild) on the original Rochester.  I was able to get the car to kind of run with this carb, but only at idle.  Before I installed it, I removed the intake manifold, drilled, tapped, and installed brass plugs into the exhaust ports beneath the carburetor so that I could run any carburetor.  That's just a nasty idea anyway, but I digress.

I warmed the engine, and adjusted the mixture needles on the Edelbrock to get it dialed in, and began working toward lowering the idle to the specified 480 RPMs.  It doesn't really run well down that low.

I managed to get to run long enough with the vacuum advance unhooked to get the timing set to 5 degrees BTDC, and set the dwell at 30 degrees as specified in the manual. 

Back the car out of the garage- ok.. try to go, and it quits.  Very frustrating. 

So this morning, I thought, maybe the fuel pump isn't doing toowell.  I don't have a gauge that goes low enough, so I just went and bought a cheesy electric fuel pump and some fresh hose, and hooked that up.

Fire it up, idles fine, kick down the idle when it warms up, fine, no problem.  Try to go- and it quits.

So finally, I decided to start advancing the timing.  Maybe this is the issue?

Now we're getting somewhere.  It's now at least driveable.  But something is just not right.  It misses and spits and sputters under load, you have to feather the gas pedal to drive it.  Once you're at speed, you can ease into it and drive it to 80MPH effortlessly... the engine is clearly good and strong.  No noises, nothing- except random misfires and popping... not good at all :-(.

The advance mechanisms seem to be working.  With the timing light, quickly 'blipping' the throttle causes the timing to retard as you'd expect with reduced vacuum to the vacuum advance.

Steadily increasing the speed of the engine results in the overall timing increasing. 

As far as I know, all is correct here...

So what am I missing here?  Why won't it run right, and why on earth should I have to advance the timing so much- that can't be right, nor can it be good for it long term.

I really want to drive this thing, hopefully someone can offer me some advice. 



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I never removed the harmonic balancer on a Cadillac. On other cars its always was a fixed position, meaning impossible to fit it incorrectly.

Reading the manual it sure does look like same thing with the 429. Should not be possible to fit it incorrectly.

If your engine and carburetor are original then it definitely is ported vacuum from the factory.
Here is quick explanation. This may or may not be the problem with your car but since you are trying to get it to run right we should go back to basics.
I will assume that you tested the vacuum advance on the distributor and it's not leaking. The shop manual calls for 5* advance at idle. Your vacuum advance adds to that as the engine starts to move the car (foot on the gas peddle) as the ported vacuum source starts to get vacuum. The car is now speeding up (slowly)ported vacuum increases, mechanical does also. Total timing is the sum of all three.

With manifold vacuum as you open the throttle plates to get the car moving the total advance suddenly drops off because the throttle plates are opening. If you set you car up to run at idle at 20* total advance and then it stumbles when trying to move the car this is probably part of the problem.

With ported advance you start to add to the timing when starting to move and with manifold advance you loose timing when your trying to move the car.

Yes there are a thousand opinions on timing. But as you stated earlier "it worked fine when it left the factory" there is not enough time my day to explain it but you tried one way now try setting everything up the other.

Lastly the shop manual says to disconnect the vacuum hose from the distributor to eliminate any possibility for error. Usually several things are going when doing timing and we don't want advance for any of it.

My car ran best with ten degrees of initial timing with the points and eight degrees with electronic. I had a ever so slight stumble at five. My vacuum advance is not factory. It gives full advance at a slightly lower vacuum signal.

Good luck
I do think your timing is your problem
You timing seems to be retarding working against the engines rotation and shutting the engine down when you go for more gasoline

You can find tDC by removing the coil wire and clicking the starter
Both number one cylinder and number 6 cylinder will be at TDC at the same time
Pull number one cylinder plug and raise the cylinder as high as it will go
Can use a screwdriver to feel it rise
Observe the location of the cranks slot position in relation to the timing plate
The crank slot SB on the plate close to the timing mark of 5 degrees ( for both cylinder one and 6)
The dist rotor SB coming to number one or number 6 cylinder at the dist cap when you observe the rotors position

Do advance the timing as needed as you saw the engine respond well and doing better doing that

Do you know the condition of the timing chain
Does the car have 25,000 miles or 125,0000 miles ?
Most likely 125
If the higher number you could be dealing with timing chain slack that is requiring you to make some timing adjustment to allow for that

Poping and sputtering is a sign you plugs are not firing at the correct time as you valves are open when the plugs are firing causing that sound and the valves both SB closed in a given cylinder when the plug fires

Did you place the correct gaskets under the Edelbrock carb as that carb will require the same gaskets under it that the stock Carter carb requires
The car will not run as it should without the correct gaskets and spacers under the Carter and Edelbrock carbs
I do not think the rodchester carb requires that same set of gaskets under it but not sure

Not sure exactly what is wrong with timing setting but something is not correct with it

Could your crank pully that you had off to paint it not be installed correctly ?

Move the dist until the engine runs better and see what the crank slot and timing plate tell you about there location when at TDC


It is an honest to goodness 25,000 original miles.  As stated, I'm friends with the original owner, and have known the history of the car.  It has its original paint in nearly perfect condition.  I can't wait to actually enjoy driving it!

I'm going to mess with the timing some more, trying some of the things I have learned here. 

The crank pulley only fits one way, I was pretty sure, but a previous response solidified that for me.

The carburetor gaskets were a bit of an obstacle, but are no longer since I have blocked the exhaust ports beneath the carburetor.  At first it was behaving just like a car with a stuck-open EGR valve- and no wonder! 

It can run essentially any carburetor now, since there are no exhaust fumes that will be introduced into the intake manifold via leaks, or otherwise.

My goal is to get it running with all original parts, including the original carburetor, although I'm not above installing the highly regarded pertronix system.  I have a 1973 Mercedes that is soon to see that upgrade, as well.

Thanks again, everyone,for your responses- I'll keep updating.

Ok.  It's on the ported vacuum port.

I said to hell with the book, and just kept advancing the timing until it stopped backfiring, and then more until it started pinging.

I backed it off a little bit, and now it runs perfectly well. 

Thanks to everyone for your help, I'll be back with more discussions relating to other parts of the car... but for now I have to go drive around!

I like my timing at 8 degrees with today pump gas
Back in the day i ran 12 degrees when the octane allowed that
The timing advance allows more low end torque and power to move these heavy cars
Advanced timing helps gas mileage as well
A win win as i see it

As a drag race champion record holder in Super Stock advanced timing was one of the keys to producing maximum HP from my full race motor

You say your timing retards when you bleep the throttle on the light
You timing should never retard but should advance from the stock 5 degree mark ( or 8 degree mark ) you use and only be incresing in degrees As RPMS increase

That might indicate you have your vacuum advance not connected in the right place on the carb
When you go to the Edelbrock carb if you use the stock carter spacer under the carb you will have to plug the stock spacer as you now have two places to connect the Pcv valve line ( one on the carb - second on the spacer )
If you do not plug the spacer you have a major vacuum leak into the intake manifold
It is not easy to see as it is hidden by the top PVC line going to the Edelbock
My idiot mechanic left the spacer unplugged when he returned my car after i had him change out the carb for me

You need to be plugging the vacuum advance line when you remove it
I do not see you saying that
That may be changing the readings you are getting on the timing plate by effecting the idle as you have a vacuum leak if you do not plug it
Just a guess on my part

What you did with the timing by advancing it is just fine and works with no harm to the engine

An old hot rod trick was to advance your timing as much as possible until the car pings and then retard it a bit
You are now running the maximum timing possible on the current octane gas available

When you have time you can look into the reason your timing marks are off

Bottom line is you are driving and enjoying your ride now

Have fun with the car

Looks like one more happy Antique Cadillac owner rolling down the road compliments of The Antique Cadillac Angels ( who live here--you know who you sre !! )

I did say retarded timing from my first post due to the engine shutting down
Feels good when i get it right from the get go


Well, I'm not at 100% with the car, but I would say at 80%.  It's driveable. Enough so that I put 87 miles on it today, and enjoyed it very much.

Advancing the timing beyond the point where it COMPLETELY stops misfiring results in severe detonation under load.  I live in mountainous terrain, so this is not an option.

So I retarded the timing to the point where the detonation is minimal, and some of the misfires are back.  There doesn't seem to be any happy medium.

On the ported vacuum, you can FEEL it come on.  It's not ideal, the car is a little jerky with this Edelbrock.  When you step on the gas gently, it starts to roll, and then the vacuum advance comes FULL on and there is this MASSIVE boost of power.  I wish it was a little bit smoother.

It's definitely jerky and a little rough off the line.  It's like it needs more timing off the line, and less timing at higher RPMs.

The engine seems most at home accelerating through the middle speeds-  in high gear, it'll pick up speed effortlessly and smoothly... I was actually shocked at how much power and how quick this car is at speed- and how quickly it accelerates.  It's impressive for such a large machine.

Also, with no advance at idle, it really kind of idles lousy....  It's tolerable, but I might just have to bump up the idle speed and play with the mixture a little bit to smooth that out.  Maybe that'll help with the off idle jerkiness too.




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