1993 Ford Taurus Wagon

I picked this car up used for about 500 dollars (I understood that there would be issues). The car is interesting in that when you put it in park after driving it for a while it stops. The lights on the dashboard are still lit, and it doesn’t sound like the problem is electrical. It just stops running. It also has a tendency to kill out at stop signs and when your foot is on the brake for too long. I have had it to three garages in this area and after hundreds of dollars of expensive diagnostic testing that I can’t afford (I am currently out of work) they usually just suggest more testing. Can anyone suggest avenues for further inquiry? Thanks in advance.

If you don’t think it’s an electrical fault, it could be that the idle speed is too low and it’s just dying when the car is stopped and no gas is being applied. Low idle speeds can be caused by a number of things, but you could try a basic do-it-yourself tuneup to keep costs low. For $500, and no money for repairs, you may just have to put up with a few annoying problems.

Does it have a tach? What is the idle speed? A normal idle speed would be in the neighborhood of 800 to 1000 RPM and should remain steady. Does the engine seem to slow down and just die out, or does it just suddenly stop running? If the idle speed is normal, and it just dies out, it could be an elctrical problem, e.g., ignition switch, or the cutoff switch connected to the shift linkage. Your lights could work at the same time the ignition is cut off.

It sounds like a problem with the Idle Air Control Valve, which is a pretty common problem. You could try removing it and cleaning it with aerosol carb cleaner before considering replacement.
It’s easily removed (couple of nuts and a wire connector) and is located near the throttle plate on the throttle body.

Problems can occur with the IAC valve and it will not set a code or cause the Check Engine Light to come on. This is what the little critter should look like.
Hope that helps.