Engine dies occassionaly when stopped

'96 Windstar 3.8L

The engine dies occassionaly when stopped. It does not sputter before dying. The engine is fine when the car is running.

The spark plug wire, spark plugs, battery, egr, fuel filter, and aic valve were all replaced about a year ago.

Does anyone have any suggestion were else I should look?

Thanks!

Hi Lbert,

Some things I would check based on my experience with 98 windstar 3,8 145K miles:

1. Run your codes to see if you have any intermittent problems stored in your car's computer and correct.
2. You can pull you idle air control valve and clean / or replace it.
3. You can check your choke pull off actuators (IMRC actuators). They have gone bad before on mine twice and this was the cause for me of the exact problem you are seeing.

Run two cans of B-12 Chemtool with the next fill-up. This almost always corrects this issue.

rtoddharris & FordBoss88, thank you for your reponse.

I usually run a bottle of injector cleaner once a year and use quality gas on the car so most likely its the IMRC actuators. I going to take them puppies apart and see if cleaning the valves helps. If not, I may have to bite the bullet and buy both.

You may have your Windstar stall at idle or when turning at slow speeds or with little throttle.

The problem for me has been that one of the IMRC actuators has developed a leak and then neither work as they should.

They are located on the passenger side of the intake manifold, look on the engine side of the alternator and there is one in front of the other. The one in front is the right one and the one in the rear is the left one. They are just a few inches apart, bolted to the intake manifold. They have an electrical connection (on the side) and a vacuum connection (on the top).

The way they are supposed to work:

1. When the engine is off, there is no vacuum to these actuators, and the butterfly valve inside the manifold that they are linked to is closed. A spring in the IMRC actuator holds the butterfly valve linkage closed.

2. At engine idle and less than 2900 RPM, there is vacuum to these actuators that overcomes the spring in the actuators with diaphragm and this opens the butterfly valves inside the manifold and this allows more air to pass into the intake.

3. At engine speeds above 2900 RPM an PCM activated switch turns vacuum off to the spring in the actuators closes the butterfly valves. This is supposed to increase performance during heavy engine load or acceleration.
I wonder....?

The problem is that one you get a leak in one of the IMRC actuators (diaphragm seal likely) s it is usually big enough that when vacuum is applied, neither IMRC gets vacuum so neither butterfly valve is open at idle. These things devleop leaks because (in my opinion after having taking a failed one apart) that they are so close to the heat of the engine that the seal of the diaphragm and housing breaks with age.

The first time I got a leak in one of these, I replaced it, it is easiest done with the alternator removed. The Motorcraft part numbers if you want to do replace this are:

CK2258 (right or front located one)
CK2259 (left or rear located one)

They are ~$180 each if you shop online, at a dealer ~$270 each.

The second time I got a leak in one of these, I decided not to replace it, since I doubted how much performance increase I got above 2900 RPM, and my problem was stalling at idle and slow turns.. What I did was remove the old one, which for me was the right one or the front located one, and plugged the vacuum line. This allowed the one remaining good one to work as it is supposed to. I then took a small spring and used it to hold open butterfly valve by connnecting it to the linkage to the butterfly valve and one of the bolts that formerly held the IMRC actuator.

As I suspected, there was little loss of performance above 2900 RPM, and the it quit stalling at idle. It took a little bit of driving for the PCM to retune with the butterfly valves open like they should be as low RPMs.

When the next one fails, I am going to do the same thing, remove it, plug the vacuum line and use a spring to hold open the butterfly valve.

I am cheap, but I really do not think that you get that much improved performance (above 2900 rpm) and do not they are worth replacing. When you take one of these apart, they are simple as dirt and Ford did a lousy job with the durability of these things and the price is outrageous for the part.

If you try this, I would like to know, and if you have any questions, let me know.

Thank goodness my 2001 has electric actuator. Of course it has other failure prone parts that I see they have changed on the 2006 Freestar too.

But yes, if you drive like a human being and if you aren't towing something then how many times do you need a big power boost above 2900 I'm wondering?

Would someone please post a pic of the IMRC actuator? Preferably on the engine.

Much Thanks,

FordBoss88

Would someone please post a pic of the IMRC actuator? Preferably on the engine.

Much Thanks,

FordBoss88
http://i140.photobucket.com/albums/r24/rtoddharris/IMRCActuator98Windstart3.jpg

This forum is awesome! My profuse thanks to "rtoddharris" for supplying the pic. I own a 2001 Windstar with the 3.8L. I am sure that it is the same.

Thanks to Hot Rod Harris! :)

My 2001 has the electronic actuator, not the vacuum operated kind. And it only has one actuator for the two banks instead of one for each.

I don't know at what point they changed that though....maybe it was midyear? Not sure. If you have the vac operated IMRC actuator and still have a problem, like me, look elsewhere, I'm guessing.

The IMRC actuator/motors are located in similar locations on all Winnies, I believe. The move from two pneumatic to one electric was model year '99.

rtoddharris, thank you again for helping us out.

How do you determine which of the two banks is malfunctioning? During idle, I can see both flaps open and close when you turn off the engine. When the car dies, you can't run fast enough to see if one or both actuators malfunctioned because they will be at their rest position when there is no power. Did you plug one up of the actuator line and hold the flap open with a device and see it the problem goes away or did you do it differently?

In addition, the car occasionally hesitates during acceleration from around 5 - 20 mph. Could the malfunctioning of the actuator(s) also cause a hesitation during acceleration or perhaps I have other problem(s) as well?


thanks,

rtoddharris, thank you again for helping us out.

How do you determine which of the two banks is malfunctioning? During idle, I can see both flaps open and close when you turn off the engine. When the car dies, you can't run fast enough to see if one or both actuators malfunctioned because they will be at their rest position when there is no power. Did you plug one up of the actuator line and hold the flap open with a device and see it the problem goes away or did you do it differently?

In addition, the car occasionally hesitates during acceleration from around 5 - 20 mph. Could the malfunctioning of the actuator(s) also cause a hesitation during acceleration or perhaps I have other problem(s) as well?


thanks,

If the actuators are moving when the car stops from idle then they may be working okay. You need to remove the vacuum lines from them and apply human vacuum to each of them independently and they should not leak at all. If one of them leaks then, that one is bad, if neither leak then you have other problems. You are not getting any check engine lights it sounds like?

rtoddharris, thank you again for helping us out.

How do you determine which of the two banks is malfunctioning? During idle, I can see both flaps open and close when you turn off the engine. When the car dies, you can't run fast enough to see if one or both actuators malfunctioned because they will be at their rest position when there is no power. Did you plug one up of the actuator line and hold the flap open with a device and see it the problem goes away or did you do it differently?

In addition, the car occasionally hesitates during acceleration from around 5 - 20 mph. Could the malfunctioning of the actuator(s) also cause a hesitation during acceleration or perhaps I have other problem(s) as well?


thanks,

If the actuators are moving when the car stops from idle then they may be working okay. You need to remove the vacuum lines from them and apply human vacuum to each of them independently and they should not leak at all. If one of them leaks then, that one is bad, if neither leak then you have other problems. You are not getting any check engine lights it sounds like?

Thank you for the suggestion. I know there was a better way to test.

I assume you do the human vacuum leak without the engine running and see if the valve holds. I will give it a try.

No, I'm not getting a CEL.

Even though you replaced IAC valve a year ago, this would be where I would look. I had one replaced on my 99 windstar and problem returned about 3 months later. I took IAC off and cleaned/lubricated it and replaced. You might try this. It's easy and free.

GWK, thank you for your input. I would certainly try your suggestion.

Thank you for the suggestion. I know there was a better way to test.

I assume you do the human vacuum leak without the engine running and see if the valve holds. I will give it a try.

No, I'm not getting a CEL.

Hey Lbert, yes, w/o the engine running... good luck.

Thank you for the suggestion. I know there was a better way to test.

I assume you do the human vacuum leak without the engine running and see if the valve holds. I will give it a try.

No, I'm not getting a CEL.

Hi Lbert,

The engine should be off when you are testing for vacuum leaks on the IMRC actuators.