97 Taurus hesitates when warmed up - runs fine when cold

Hi,

I've got a 1997 Ford Taurus 3.0L EFI 6cyl that runs fine cold but when it warms completely up it starts to do this on and of hesitation thing where it hesitates for a fraction/then runs for a 1/2 sec then hesitates again.

I thought maybe it was a vacuum leak but can't find it if it is.

Any thoughts or links?

Thanks.

Your description sounds like it could be an ignition misfire as well. Do you know when the last time was that the car had a tune up, including spark plugs and spark plug wires?

-Rod

Your description sounds like it could be an ignition misfire as well. Do you know when the last time was that the car had a tune up, including spark plugs and spark plug wires?

-Rod

Well, why would that have anything to do with running fine cold and then when it warms up, run as described?

I appreciate the response but I'm not going to change anything until I find out what the problem is, or at least what sounds to be a reasonable explanation.

Rods question is trying to determine the overall state of the vehicle and a little bit of its history. That sometimes helps in narrowing the immensely vast array of possible causes for this type of vehicle behavior. Is your Check Engine Light (CEL) on? If so, then go to an auto parts store and ask to have the codes read. I'm not as familiar with the engine you have (called a Vulcan). I have the 3.0 L dual overhead cam (called a Duratec). On mine there is a vacuum line that goes underneath the intake manifold that likes to get a hole in it as it ages. I suggest following each one of the vacuum lines and inspecting closely if you suspect that is the cause.

Well, why would that have anything to do with running fine cold and then when it warms up, run as described?

I appreciate the response but I'm not going to change anything until I find out what the problem is, or at least what sounds to be a reasonable explanation.

Things expand when hot. Cheap or worn spark plug wires can go intermittent as they heat up. If these issues started shortly after a tune up, attention could be focused on the work performed as part of that tune up, such as if the "budget" spark plug wires were installed.

The more information you can provide, the better the fidelity of the responses you'll get.

-Rod

MAF or IAC or EGR.
Or even the EGR sensor.

Mass Air Flow sensor or the Idle Air control sensor/valve.

And of course, a vacuum leak.