QuestionHi Dick,
I have a couple of questions about my '64, which has been in my family since new, so I have a good knowledge of what's been done (almost everything over the years) since it was new.
The car was in storage for 3 years with bad gas in the tank. I've not had new plugs, points etc. put in, run most of the old gas out of the tank and filled it with 94 octane plus a cup of methyl hydrate. It's starting to run better, but still coughing quite a bit on cold start until it gets up to temperature. There's also a bit of a lag on the carb when it's given gas. Once its up to temperature it runs quite well except the same little aputter when it's given gas.
So my first question is what you would recommend I do next, other than run the full tank of new gas through and hope for self correction.
The second question I have is about the carburetor itself. It's a 2 barrel, and I was wondering if I should consider replacing it with a 4 barrel. The motor is a 283. What type of benefits do you think I would gain? Is it a matter of simply replacing the old with the new, or does it involve replacing the intake manifold and converting the exhaust manifold to dual exhaust as well?
Finally, assuming that putting the 4 barrel in is not too costly for the additional benefits, would you recommend going with the original factory 4 barrel that was available on the 283, or some other type of carburetor?
Looking forward to hearing from you.
Regards, Larry
AnswerYour current symptoms are of a dried out leather piston on the accelerator pump in the carburetor.
To prove this, with the engine turned off, take the air cleaner off and look down the front barrel of the carburetor, while you hold the choke flap open so you can see down it's maw with a flashlight. Now, have a helper mash the gas pedal to the floor - there should be a healthy squirt of gas out of a nozzle and down into the front barrel of the carburetor - I'm betting there will be just a dribble or less - that is what is causing the stumble on "tip in" of the throttle. This often happens when a car is allowed to sit undriven - the leather dries out unless it is kept moist with gasoline.
This easy to fix, if you are handy with tools. If you take the top of the carburetor off, you'll see the pump action when you operate the accelerator linkage. It is pretty obvious how to get the leather piston plunger out by disconnecting the linkage to it. Do that and then soak the leather plunger in engine oil overnight. In the morning, work the leather with your hands to form it back into a cup shape which makes a nice fit in the well it moves in. This should restore normal action to the pump, and your problem should go away.
As for changing to a 4 bbl, it does require changing the intake manifold and the air cleaner, plus the linkage and, assuming the car has automatic transmission, the kickdown linkage. I do not recommend you do this - the difference in performance and economy is very small - definitely not worth changing an original setup for in my opinion.
The exhaust system is not affected by this change, it is an independent system, so you can convert the car to duals, if you want, but again, there is almost no change in performance or economy, and it will affect the original status of the car.
Dick
