'99 Starting/dying problems w/warm motor

1999 Ford Taurus mileage: 120000. The Taurus has an occasional warm re-start problem. Also the car will die at low speeds or idle after running for a while. I can't have someone look at it because it is random. It typically occurs in warm weather. After the car has been run for a while and shut off, when I attempt to start it again it will either not start or idle very rough. Stumbling, stalls, etc. force me to feather the throttle to keep it going sometimes. If the car is cool I have no starting problems. The problem seems to be slowly getting worse.

I have changed the IAC valve, Engine Coolent Temp Gauge and the fuel filter is less than a year old.

Which engine does your Taurus have (12V, 24V, 32V)?

Just before the engine stalls, does it do anything odd such as run rough or drop in idle speed? When it idles very rough, what does the exhaust look like? If it's very dark, you are probably running rich. You can pull a few spark plugs and see if they are coated in fuel. You can also try holding the throttle to the floor (Wide Open Throttle - WOT). This will shut off the fuel pump and may allow you to get the car restarted if the air/fuel mixture is too rich.

If the exhaust appears relatively normal, then you might have low fuel pressure. Check the fuel pressure when the car won't restart. If you have very little fuel pressure, you might have a fuel pump that is failing. Similar to starter motors, they can work fine when cold and fail when they warm up after running awhile since the pump should be constantly running while the engine is running.

Post back with details and we'll see if we can narrow your search a bit more.

-Rod

It is a 12v and the problem is getting worse. Died in traffic on the highway last night. The temperature outside was around the mid 80's. Since last post I have changed the Plugs/wires and ran fuel system cleaner thru it. Plugs looked normal except 2 of them were slightly darker. No exhaust color. Holding the throttle wide open did not help restart.

I am leaning toward replacing the Fuel pump. Is this a difficult process? From the Haynes book it doesn't look to hard.

Thanks for the help.

The difficulty level of replacing the fuel pump is going to depend a lot on your skill level (no offense) and what tools you have available (impact wrench, jack, jack stands, etc). I believe it still entails dropping the fuel tank to access and replace the pump. You will want to be certain that the pump is the problem before doing this, and hopefully if it is, the tank will only have about 1/8 tank of fuel at the time.

Also, you can expect some of the fasteners to be seized and possibly even break during the process.

You may want to pick up a fuel pressure guage with the Ford adapter at your local auto parts store and verify the fuel pressure during the no start condition. The pressure guage is pretty small and could fit under your seat, in your trunk, in the center console, or possibly even in the glovebox, so finding space to have it with you shouldn't be an issue. It will cost you less than replacing a fuel pump that you don't actually need as well.

-Rod

If you have two people with you when it does not start do this (BE VERY CAREFUL!).

Open the hood and look for the fuel rail. On the rail there should be schrader valve (looks like tire inflation valve). Take off the cover cap and have the second person crank over the engine while you place a rag over the valve and press in the valve with a small screwdriver. You should get a decent amount of fuel squirting out (BE CAREFUL!). If not, you probably have a bad fuel pump. This happened on my '99 Taurus 24v a few years ago.

UPDATE:
I was able to get my car to act up when I stopped by the dealer last week. Yes it was the fuel pump and I just went ahead and had them fix it.

Thanks for all who helped.

I hope it didn't cost too much. Car repairs aren't fun :banghead: .