Stepping on it leaves Lincoln Town Car stalled in the drive-thru

Dear Car Talk:

Hi. I have a 1989 Lincoln Town Car that sometimes cuts out when I give it very little gas — like when I’m inching my way along a drive-thru line.

Any idea what could cause this problem? I’ve replaced the spark plugs, wires, cap, fuel filters and fuel pump.

— Joshua Thanks.

Wow, Joshua. An ’89 Town Car is a beast from another era. That car probably dropped a lot of people off at the Pan American Airlines terminal.

This thing is so old that’s it’s carbureted. And I think that’s where the problem lies.

A carburetor has a little pump built into it called the accelerator pump. And the

accelerator pump’s job is to squirt in a little extra gasoline when you first step on the gas pedal.

Once the gasoline is flowing, the suction created by the pistons does its job, and the carburetor has all the fuel it needs to respond to your acceleration requests. But in that first second or so, right when you go from idle to accelerating, if the engine doesn’t get that extra shot of gas, it’ll stall.

So I think you have a bad accelerator pump.

The bad news is that you probably didn’t need any of that other stuff you bought and installed: the wires, plugs, fuel pump, etc.

But the good news is accelerator pumps are cheap.

You can probably find one online for about $10.

And if I remember correctly, on this car, the accelerator pump sits right on the front of the carburetor, and attaches with four simple screws. One of which you’ll certainly lose if you try to do this yourself. But it’s a job a DIYER can tackle.

However, you could also look for a mechanic who remembers how a carburetor works.

If you pay him for an hour’s labor, he might not only swap out the accelerator pump for you, but also blow out the accelerator pump’s fuel passage with some carburetor cleaner. And that’s not a bad idea, too, at this point.

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