I completed changing out all (8) spark plugs last night with new Autolite 216s gapped at 0.032". The old plugs had all sorts of issues to include (3) with non-compressed plug rings (finger tight) and (2) with less than 0.24" gaps. I thought I had this whipped, so I immediately took her out for a test drive only to face disappointment ---the performance didn't change much. The idle vacuum @450 rpm is still a mere 15" and the engine still stumbles/misses beginning at 3,000rpm. Keep in mind this stumble/miss occurs as I gradually approach 3,000 rpm (I'm not instantaneously pedaling it to to the metal). 

So now I find myself facing that old, "is it the ignition vs. carburation" dilemma. A couple of more observations I'd like to share with you:

1. When in Neutral and idling with no load, the engine's rpms will instantly rev from 450 rpm  to 4500  - 4700 rpm each time I wrap the accelerator pedal. I can do this 4- 5 times in quick succession and the engine responds flawlessly. Wouldn't this TEND TO INDICATE the ignition system is PROBABLY not the primary issue? As a minimum I believe this allows me to rule out bad points or a bad condenser.  However the dizzy curve still remains in question.
    
2. Regarding the 2140 Teapot ---I must fess this is my first rodeo with such a carb. It bothers me that the choke tube, which projects up through the base of the carb and into the carb air- cleaner (as a source of clean air), is CONSTANTLY DRAWING VACUUM (to heat the bi-metallic spring in the choke assembly). Is this tube supposed to constantly suck air or should it only draw air during the choke heat-up period? The intake with the Integrated choke housing is also a first for me (see pics below)

Thanks for all of your support on helping me "debug" this engine. The previous owner did his part in getting the engine reassembled and stabbed back into the bay but he unfortunately "ran out of time (88) and funds" to finish sorting her out for reliable performance street use. This has become my job and contribution to our beloved hobby (bedeviled at times too).           



   
    

10% ethanol in the 87 & 89 grades just complicates the problems even more.  In checking the ethanol content here, I have found as much as 30% ethanol coming from pumps labeled as 'Contains up to 10% ethanol'.  You really don't know what you have until you do an actual ethanol content check.

Another plus side to any fuel with a reduced ethanol content is the shelf life of the fuel is further extended.  This is of benefit to those who do not drive their vehicles enough to turn over the fuel in tank every ninety days.

!!! AMEN !!!

And you are not sure of how much water is in the station fuel tanks or what quality fuel you are buying (some distributors may add more ethanol to the mix to save costs). Without EVAP, it is a losing proposition. TOP TIER FUEL has a meaning.

Also, if the car sat with fuel in it, most likely the system is fouled with varnish and rust (incl mechanical pump and carb). When you do a pump volume delivery check and catch it in a glass jar, you will see any rust/sediment and then let it sit for awhile and you will see the water content as it settles.

____________________________

You will want to run 91-93 octane gasoline not so much for the octane but for the reduced amount of ethanol in the premium grade versus what you find in the 87 & 89 grades.  If you read the small label on the pumps, it will say ‘Contains up to 10% ethanol’. The increased ethanol content in the 87 and 89 octane grades will many times contribute to off idle and hesitation issues.  Even with the reduced ethanol content in the premium grades (3-5% in my part of the country), I find it necessary to jet the primary side carburetor jetting up a couple of numbers in the Teapot carbs in which to compensate for the ethanol content.  10% ethanol in the 87 & 89 grades just complicates the problems even more.  In checking the ethanol content here, I have found as much as 30% ethanol coming from pumps labeled as 'Contains up to 10% ethanol'.  You really don't know what you have until you do an actual ethanol content check.

Another plus side to any fuel with a reduced ethanol content is the shelf life of the fuel is further extended.  This is of benefit to those who do not drive their vehicles enough to turn over the fuel in tank every ninety days.

Lorena, Texas (South of Waco)

BEFORE I FORGET ! (and it is becoming common lately) ...

The DIST CURVE should be shown in your WSM under IGN - SPES for the engine. That may help to verify the correct curve and if anything might be frozen.

The machine shop must have just stuck the old plugs in thinking the owner would take care of that. Loose plug(s) may be your compression loss. One way to find out.

As for the secondaries being adjusted incorrectly, usually that is done to try and hide a big cam. Again, settings and adjustments will be found in the WSM  under FUEL - SPECS.

Did the seller start a restore and lost interest?

Keep us posted on this thread as you have an interesting project going (and yes, I am jealous).

____________________________

I just pulled the plugs on the Passenger side ---Cylinders 1,2,3,4. I found that the plugs on 3 & 4 were barely screwed in! The weight of the wrench turned them off!!

Would this help explain why these cylinder plugs are wet (see pics)? Cylinders 1 & 2 tips are light grey, 3 & 4's dark and wet. The gaps are also all over the place ---rangining from 0.024 to 0.037.

I can't say these issues were the cause of low vacuum problem and stumbles ---but certainly weren't helping....

What say you?

I will plead ignorance on the Lincoln Y, but 7* initial timing seems low even for a stock, low compression engine.  Have you tried to set the initial timing up to 10*-12* and checked vacuum?  I bet the vacuum will come up to 17" or more with more initial timing and not ping while driving.  It might actually help your stumble at 3000 rpm.  It should not hurt to try more timing as long as the total is not over ~38-40* with no vacuum advance.  Joe-JDC

JDC

Fresh 87 octane gas. Figure this 8.0 CR engine doesn't need 89 or 91 (plus it's 0.30 cents/gallon cheaper than 91). The cap and wires sure look very new as did the points and condenser when I inspected them and set the gap. 

The 7" timing tape is correct. It's the diameter of the HB and when placed on the only three original markings --0, 10 BDC and 20 BDC ---it aligned perfectly. 

I haven't checked and verified the fuel pump pressure  (yet...?).

The idle screw being all the way backed off also bothers me bunches. The initial thought is maybe the secondaries are too far open? Searching for vacuum leaks that might explain everything hasn't delivered. I'disconnected all of the vacuum lines (brake booster, fuel pump wiper assist, etc,) and sprayed starter fluid on the typical offenders but thus far have come up empty handed. 

Back to firsts ---I'll change the plugs and post pics with 48 hours. Stay tuned,,,

(She appreciates compliments being a whistle straight and pampered black 4-door. Doesn't suit every man's taste but there ain't no denying she's a plus-sized looker!  ; - ).

Stale ethanol gasoline ...

How long did the car sit with fuel in the tank?

BTW - Did you check fuel pressure and delivery volume? Clean filter?

It is a beautiful car. 4DR?


READ THIS - https://www.onallcylinders.com/2021/09/24/what-is-a-leakdown-tester-and-how-do-you-use-it/

If thinking of doing a compression check. Also report or post photos of the plugs when pulled.

____________________________

WOW,  Nice car.....Lou

I think I'd start with a tune up.  Fresh plugs, cap, condenser, points...sounds like your wires are new...maybe get a cheap replacement set to verify that yours are good.  
Then I think I'd chase timing.  Are you sure you have the right timing tape?  I just picked up one of those timing lights that you set your advance on a dial and then match up the TDC mark...it advances the flash so you don't need timing tape.  It worked pretty well.

The other thing that bothers me is that your idle set screw is turned all the way out.  I know nothing of those teapots but that idle screw situation doesn't sound like any carburetor I've ever messed with.  Maybe try a known good one...or if you don't know anyone WITH a known good Teapot, then maybe even slap an adapter with something else that's known to be good just to see how it runs.  Would that even work with your distributor?