1963 Mercury Comet Engine cuts out

mercury

#1

My son’s car has a strange problem. When turning left the engine will cut out. I checked under the hood and there are no wires or lines being pinched and it doesn’t appear to be a vacuum line. When you straighten the wheels, the car keeps going as if nothing had happened. This only happens on relatively sharp left turns.


#2

Some–perhaps many–older cars suffered from gas starvation on sharp turns as a result of carburetor problems, even when they were new. And, in many cases, this would happen only on left turns, or only on right turns–depending on the make & model of the car.

Especially in view of the age of the car, I think it would be a good idea to rebuild (or replace) the carburetor. However, at this point in our history, finding a mechanic who still knows how to rebuild (or, even to adjust) a carburetor could be dicey.


#3

In particular, I’m thinking the float isn’t working. Perhaps it has become saturated or punctured or just simply out of adjustment.


#4

@VDCdriver and @CapriRacer have nailed the problem. This was a common problem many years ago and it generally has to do with the float being unable to close off the fuel pressure. When this happens…the engine is flooded for a moment and it stumbles or dies depending on the severity of the flooding. Carburetors with “straight ahead” float pivot points were less susceptible to this problem. Carbs with right or left pivot points had a real problem on sharp turns depending on which way the vehicle was turning. Rebuild the carburetor and replace the float.


#5

Sounds like a sticking float. Our 72 Olds did this on right turns, until we got it fixed.


#6

Which engine does the Comet have? Is it stock? Is the transmission a manual or automatic? Does the car have power steering?


#7

If it were the float, the issue would be that the float is set too low. I’d suspect a piece of debris around the main jet that blocks the jet when turning in one direction.


#8

Before you tear into the carburetor, inspect the wiring going to the primary side of the distributor. Check for bare spots where the wire might ground out against the engine block. It may be the float in the carburetor, but from your description " the car keeps going as if nothing had happened. This only happens on relatively sharp left turns", it almost sounds as though the ignition is cutting out.


#9

^
Triedaq–If I am not mistaken, “Gus” from The Model Garage found the same problem on a car that he worked on in the '50s. Yes, this is a definite item to look at.


#10

@VDCdriver–I remember Gus Wilson finding that problem on a car in one of the “Model Garage” stories in Popular Science. I also saw a car that had the problem that was being repaired in a service station where I traded. The mechanic who did the work showed me a bare primary wire that would contact the engine block on a sharp right turn. It wasn’t my car, but this mechanic really liked to show me an interesting problem that he had solved. I learned a lot from him and the Model Garage stories in Popular Science.
I was taught that “carburetor” is a French word that means “leave it alone”. I always looked at the ignition system first when problems like the one described above occurred.


#11

My favorite item from The Model Garage was the case of the woman whose car only ran badly (and smelled of gasoline fumes) after it had fully warmed-up. Gus found that she was hanging her purse on the pull-out “purse hanger” that the vehicle manufacturer had thoughtfully provided.

The pull-out “purse hanger” was the control for the choke.

:-))


#12

@VDCdriver–I liked the Model Garage stories that involved the town’s cheapskate Silas Barnstable.


#13

A 1963 Comet. Wow! A vehicle I could actually work on. No computers, electronic fuel injection, modules, sensors, or codes. I am puzzled by the wiring going to the primary side of the carburetor. I owned 2 1963 Ford Galaxies and don’t recall carburetor wires.


#14

I think I said the primary side of the distributor.


#15

Triedaq Yes you said distributor preceded by carburetor in the same sentence. I’m getting old. The only wire I remember going to my Ford distributor with the exception of coil and plug wires was the ground wire for the points from the negative coil post. I am not familiar with the primary side of a distributor. Did you mean wire from ignition switch to positive coil post? Maybe it has just been too many years (decades) since I have seen a carburetor, coil, distributor, or a wire that I had a clue what it was for with the exception of spark plugs.


#16

@sgtrock–the primary side of the distributor contains the distributor points and condenser. The points serve as the switch that completes the ground from the primary side of the coil. If the wire from the coil to the distributor finds a path to ground before the ignition points, there is no spark. The distributor primary side grounds through the engine block.


#17

Triedaq Thank you. I guess I still remembered the concept I don’t remember the term primary side of distributor that is what confused me. Back to OP’s problem There were carburetors for road and circle track racing with fuel bowl baffles to help prevent fuel starvation from centrifugal force. If the OP’s float is out of adjustment and only allowing partial filling of the bowl it could create a similar problem when cornering. The only thing I miss about carburetors is the acceleration/deceleration response. That was lost in the mid 1970s with smog pumps. retarded timing, and the deceleration valve. My 2010 KIA Forte SX with throttle by wire has a very aggressive throttle for acceleration but a computer simulated deceleration valve. I have no clue how to diagnose or repair anything engine related in my KIA but at my age love the ease of operation and reliability.


#18

Thanks for all of the suggestions. It is the small (I think 2.4L) straight 6 with the “Merc-o-matic”.
It is not a wiring problem because I have been through that. I guess it must be the carb.


#19

2.4l = 144 CID, the smallest of the Ford I6 engines. My Mustang had the 170 CID with a manual 4 speed. That 144 with an auto must be ‘relaxed’, I’d guess.

What’s been done to the carb? If it’s old, you can either rebuild it, or send it off to be rebuilt. Rockauto will do it for $160 or so.


#20

If you have a Ford/Motorcraft 1bbl carburetor it is most likely the cause of your problems.