1996 3.8 intake manifold runner control stuck open

[TCsNicNac]

Originally Posted by wiswind

The default position of the intake manifold runners is OPEN. They are open when the car is not running. When you start the car, vacuum is applied to the actuators, and they close.
Above a certain RPM they open.
There are 2 of them. One for the front bank of cylinders, and one for the rear bank of cylinders.

With the car OFF, you can try to move each one....and see if it moves.

The actuators can go bad. On my '96, the actuators get their vaccum source through red lines that connect to the top of each actuator.

Here is a link to some pictures of my '96....that may help you to locate the actuators...as well as a few other things. You can click on "view full size" to blow the pictures up to see more detail.

http://community.webshots.com/album/201931518cScpNK

Once again this forum and it's wonderful members, like you, have helped me immensely! Knowing where to look and what to look for was invaluable. Found a missing clip that holds the arm into the lever that controls the valve. Should be fine now. THANKS!!!! Tom C.

[bubble22]

After a long research

part # for irmc solenoid ford 3.8l

is e7tz-ph465a-a valve (as shown on the box)

[GaJim]

Great thread, guys.

1998 Windstar, BTW.

So if I'm following the logic here.......I checked the vacuum and have a small amount of vacuum on the rear most IMRC valve (the one closest to the firewall), but can't seem to detect any on the front valve (the one closest to the front of the car). That would seem to indicate a vacuum line leak, or possibly a blockage, on that front valve line, correct? Since BOTH have to have vacuum for BOTH to work, I can probably just replace that one short piece of line and it should clear up, right? TIA for the help.

Jim

[GaJim]

Took a break and decided to look at this again. The one thing I didn't try the first time around was to remove both vacuum lines at the same time. When I did that, I have good vacuum on both (by covering both lines with my fingers). Seems I have "pretty good" vacuum when I disconnect the back line, but almost none when I disconnect front line. I'm guessing that means the back IMRC has failed and the front one is probably on it's last leg? I was really hoping this would turn out to be a vacuum line problem. But it looks like I'll be spending money on new IMRC(s). Dang.

Jim

[12Ounce]

One poster, long ago .... may have been on another forum .... tried repairing the broken diaphragm with some success. I have no knowledge of what was required ... but it sounds like something I would try.

[GaJim]

Originally Posted by 12Ounce

One poster, long ago .... may have been on another forum .... tried repairing the broken diaphragm with some success. I have no knowledge of what was required ... but it sounds like something I would try.

Ya know what, I was thinking about that driving home this afternoon. I may take a shot at that. After all, it's already broken. All I can do is break it more, right? Thanks for the tip.

Jim

[12Ounce]

I would also take a look at replacing with a different pneumatic actuator ... such as the one on D's '93 4 cyl Nissan truck ... "bullet proof". Pretty sure it could be Gerry-rigged into place.

[jimh]

This is a very educational thread. My 1996 3.8 has both codes for IMRC stuck open. I have them both wired closed for the time being (might be a vacuum problem upstream). Actually seems to run better off the line. However, now I have P0171 and P0174. Lean on both banks. The one by the firewall would not stay open when pried open and figure over the vacuum hole. Replaced bad with Rock Auto but still codes. Electric connection seems to be correct since code when away with wired shut solution. So I guess work on finding vacuum leak and MAF? Any help is appreciated. thanks

[onit]

I used the same one from rock auto if you got the dorman one it will not work. Someone on this forum mentioned that the only ones that work are from the dealer. I am surprised that you did not get the buyout offer from ford. I got mine a few months after i had donated my winnie. Anyhow hope this info helps

[scubacat]

Originally Posted by jimh

This is a very educational thread. My 1996 3.8 has both codes for IMRC stuck open. I have them both wired closed for the time being (might be a vacuum problem upstream). Actually seems to run better off the line. However, now I have P0171 and P0174. Lean on both banks. The one by the firewall would not stay open when pried open and figure over the vacuum hole. Replaced bad with Rock Auto but still codes. Electric connection seems to be correct since code when away with wired shut solution. So I guess work on finding vacuum leak and MAF? Any help is appreciated. thanks

That usually excess means air is leaking into the intake somehow. With the engine running, you can carefully spray carb cleaner around the intake. When you find the leak, the engine will stutter or run rough for a moment. Check the intake hoses, air filter housing, etc.

If you've never done it (or it's been a really long time), you might consider replacing the upper intake gaskets and the PCV valve and grommett. Those are pretty cheap parts that can also cause an intake leak that's difficult to detect.