Hi guys. Looking for a little (or alot) of help. I may be listed as a new user, but have used this forum for help for many years.

Currently I have a 2000 Mercury Sable (Ford Taurus) with the 24v DOHC. While driving down the road, it will shut off. No sputter, no shaking, just off. Some days it happens, some it doesn't. Seems more current on warmer days, like something gets hot and shorts. I turn the key and it will not do anything, no crank, no fuel pump. Once it cools, it starts right up and drive off.

I have tried a new ignition module under the steering wheel, neutral safety switch, and two coils on plugs (has six and 2 were replaced before).

What can this be? I figure its got to be a short, but can a bad coil stall the car, and stop the ignition and fuel pump?

 

When it shuts off, do you have power to the dashboard and lights?
Do you have any other electrical issues with the car?

There could be a problem with the alternator and battery. I would do a battery load test and inspect all connections/ cables and ground connections.

 

Yes the lights works, dash works, everything but cranking and fuel pump. When I turn the key with the headlights on, it does not even dim them.

 

You may have a problem with the anti-theft system.
You should have a second key, try that key and drive it a while. See if the problem goes away.

 

Thanks hanky. As usual you are on to something. I don’t know if this is a continuation of the problem or not, but it still stalls, but i can usually get it started with the "new" key. I finally noticed that the theft light stays on (only light on) while it struggles to stay running. I have been having trouble keeping it running in the mornings now too. I am not sure if that would be same issue or IAC (which I just cleaned) or ERG (which I tried to clean). I am really frustrated. Can I get around the stupid PATS or not? If I could, at least I could rule it out.

 

Let's see if we can eliminate some possibilities.
Do you have other metallic trinkets on the key chain/ring?
Have you tried using the key by itself?
Are there ANY aftermarket accessories installed on the vehicle?
If possible can you have the PCM checked for any stored codes ?
Some auto supply stores like Autozone, Advance will check for any codes at no charge.
The particular system in your vehicle will shut off the injectors and disable the start system if there is a problem with info from the coded key. Lets see what answers we get and go from there.

 

OK. So I have tried a number of things. First I am using my second key with no other keys or items near it. The major shut downs have not occurred lately, of course it has not been hot, which seems to make it act up. It still wants to stall but if I feather the gas I can keep it running, which while this happens the theft light has been on and off. Have had issues some cooler mornings it misses and takes awhile to straighten out. The other day i drove home from work, about 30 min,drive. It was hotter and started missing bad about a mile from home. Got home and ran codes. Said d e and f coil was miss firing and cylinder 1 and 2 misfire. Turned off. Came back 15min later started up no prob. Been running codes and been getting nothing. so to sum up, misses sometimes, still tries to stall.

 

I hate trying to type this on a phone. I need to clarify. When I say it was hotter, I mean the ambient temp, not the engine. The whole time the engine has been running around 190 200.

 

Crank sensors have been known to get troublesome when they get hot.
I have often confirmed this by splashing cold water on it and see if it temporarily stops the problem.

 

Replaced the crank sensor awhile ago. The cam sensor do the same?