Is there piqued interest in unintended acceleration?

Dear Car Talk

Dear Car Talk | May 01, 1990

Dear Tom and Ray:

We have a 1987 Mercury Grand Marquis. The engine seems to accelerate all by itself at slow speeds. I have to be very careful parking the car, or I will run into something. I've heard about unintended acceleration. Is that my problem?

TOM: Isn't it funny how as soon as a new phenomenon is publicized, suddenly all kinds of people think they've experienced it? Lately we've noticed that a lot of people have become interested in unintended acceleration. We've also noticed that this interest seems to develop right after they've driven up on their neighbor's lawn and over some prize winning tulips.

RAY: I guess when you're parked in someone's else's flower bed, grumbling "unintended acceleration" sounds a lot better than "whoops, wrong pedal." Anyway, we don't think all those tulips died from unintended acceleration, and we don't think that's YOUR problem either.

TOM: There are a number of fairly simple things that could create the symptoms you describe. The most likely is an idle speed that's been set too high. If the idle speed were too high, the car would feel like it wanted to pull away when you had your foot on the brake, but would operate perfectly at normal and high speeds.

RAY: Start by taking this car to your mechanic and having the "curb idle speed" checked and adjusted if necessary. If the curb idle is OK, have him check the idle speed control motor to make sure it's not causing surging, and have him check the throttle to make sure it's not sticking. If none of those makes a difference, I'd move to a bigger city where everybody bangs into the cars around them when they park.

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