Vintage Mustang Needs a Vintage Mechanic

Dear Car Talk

Dear Car Talk | Aug 14, 2012

Dear Tom and Ray:

I have a 1966 Ford Mustang 2+2 (289-cubic-inch) V-8 engine with four-barrel carburetor. It has more than 170,000 miles on it. It starts right away, but when I shift the automatic transmission to Drive or Reverse, it dies out every time. I changed the fuel pump and the fuel filter, but the problem persists. I would very much appreciate your advice or any suggestions I might pursue. I have had this car for almost 46 years now, and I cannot bear to part with it. Please help. I am 72 years old, and on a limited income. Mahalo.

-- Onofre

TOM: The problem is not the age of your car, Onofre; it's the age of your mechanics! They're all too young now.

RAY: We have a bunch of guys working in our shop, and none of them have ever worked on a carburetor, and wouldn't know a carburetor problem if it crawled up their pants leg, bit them and left a huge rash on their tuchus.

TOM: To me, this sounds like a classic "choke pull-off" problem. When a cold carbureted engine starts, the choke is automatically engaged in order to reduce the amount of air going into the cylinders (that's why it's called a "choke"). This temporarily richens the mixture (more gas, less air) and makes a cold engine easier to start.

RAY: But then, after a few seconds, once the engine is running, the choke is supposed to immediately "pull off" partway (it slowly pulls off the rest of the way as the engine heats up).

TOM: If the choke doesn't partially pull off immediately after the engine starts, the fuel-air mixture will be too rich, and the car will be susceptible to flooding out and stalling. And when is that likely to happen? As soon as you put the car in Drive or Reverse and ask the engine to actually do some work!

RAY: I mean, there are other things that could cause the stalling. Weak spark for any other reason would do the same thing. But if you drove (or got pushed) into my shop, the first thing I'd do is check the operation of the choke pull-off, and if it's not working, replace it. You may need to buy a whole new carburetor in order to get a new choke pull-off, in which case I'd recommend an aftermarket carburetor with an electric choke.

TOM: So, you need to find somebody who knows what to do when he sees a carburetor. I have a few ideas for you. One is to ask other classic-car owners you know for the name of a mechanic they like. Or, you can call around to your area shops and ask if they have anyone there who knows carburetors. Most likely, you'll get a frightened silence on the other end of the line, the handset will drop and then you'll start hearing crickets. But you may get lucky and find a place that still employs an old-timer.

RAY: Or, you may need to get more proactive than that. You may need to start visiting local old-age homes. Walk around and shake everybody's hand and say "hello." And when you meet the guy with the permanent grease stains under his fingernails that he still can't get out after 20 years of retirement, tell him it's his lucky day -- you're taking him on a special outing! Mahalo, Onofre.

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