Tom

Tom,

Q I bought a ‘96 Grand Marquis with only 36,000 miles in mint condition.

While driving at night in Colorado more than 10,000 feet above sea level, it
stalled and would not restart until it sat for ten minutes. The fuel pump was
running, and a new fuel filter was in place. When the car was put on a lift I
noticed that the fuel line ran only a couple of inches from the exhaust. Is
there any connection between heat from exhaust, slow driving speed, and
lower air pressure at high altitude? Or does the computer have to be reset for
high altitude?

Dave—Katy,  Texas

Dave,

A Sounds like you either work for, or want to work for, NASA. I think you

are barking up the wrong tree. Unlike carburetors, the fuel system doesn’t
rely exclusively on atmospheric pressure to move fuel to the cylinders. On
your fuel-injected engine, the fuel pressure regulator is sensitive to changes
in air pressure and will actually increase system pressure automatically.
Increasing fluid pressure increases the boiling point. That’s why we
pressurize cooling systems. By increasing the pressure in the fuel lines, we
decrease the likelihood that a vapor lock would occur.

Many times, problems like the one you describe become apparent
because not all of the maintenance was performed on the vehicle at the
appropriate times. Air filter, breather filter, PCV valve, plugs, wires, and so
on should be replaced routinely. It may be the result of simple neglect by the
previous owner and all your car needs is a good old-fashioned tune-up.