2000 Mercury Sable starts but doesn't run

A month ago I was pulling onto Hwy 5 and the car stalled. I pulled over and restarted the car - no prob. But, the check engine light came on. I took it to the shop and they said that the check engine light code said there was a problem with the fuel pump. Unfortunately they couldn’t find anything wrong with the pump. They reset the check engine light and it didn’t come back on and the car ran fine…until Sunday.

On Sunday, I tried to start the car. It would start but only ran for a second or two and then shut down.

I took it back to the shop thinking it was the fuel pump failing but they say the fuel pump seems ok, they’ve replaced the fuel filter but it still won’t start. They seem to flummoxed.

Any suggestion on what might be going on?


Ummmm, how did you get it back to the shop if it didn’t run? What were the codes? Did it continue to not run, does it run sometimes or does it always start and stall?

There is no error code that is associated with a check engine light that can tell you that there is a fuel pump problem. So find out what the exact code was (format: “P0123”) and post it.

They may have pulled something like a lean condition code (e.g. P0171 or P0174 or both) and then checked fuel pressure or something. Or there are a few codes that would lead one to suspect a fuel pump problem. And then they would check the fuel pressure. But if they did actually find the fuel pressure too low then they probably wouldn’t have told you that they couldn’t find any problem. So, nothing that you’ve said really adds up. Find out more about what - exactly - they have done and tested and how.

Off hand, my first thought was that you have a bad idle air control valve (IACV). This can make a car stall when you come off the gas pedal (which you might do to take a highway ramp), and can make it start, run for a second, and then die immediately.

But it could really be any number of other things too including a failing fuel pump. I have no idea why this shop would be “flummoxed.” It’s not that hard to find out. Did they check for spark? (How old are your plugs and wires? ) Did they actually check the fuel pressure? (How old is your fuel filter?) Did anyone try to keep it running by using some starting fluid in the intake? Did anyone try to keep it running by holding down the throttle some? (This would compensate for a dead IACV).

So anyway - a car that won’t run is a very basic - perhaps THE most basic thing for a mechanic to sort out. If you want help remotely report more about what has been done and why it seems so difficult.

If it only runs a few seconds, sounds like fuel pressure. A fuel pressure guage would quicly tell if it is the pump. Check mechanics files for a different mechanic.

I assume they checked the fuel line pressure? It sounds like what they suspect after having checked it out is that the fuel line is losing pressure after the engine is shut off, and then needs to be repressurized when you start it up again. There’s a check valve that prevents this, but yours may be tired.

Try this as an experiment. When you start the car over the next week, turn the key to ON for 4 or 5 seconds before turning it to START. If that clears the symptoms up, you then know what needs to be done to fix it, or (my preference on a car this age) you can simply build the 4 to 5 seconds into your normal starting procedure. I had an old truck years ago that did this and I simply built the extra seconds into my starting procedure.

Post back with the results of your experiment.